20635987680 has 1152 divisors, whose sum is σ = 93360024576. Its totient is φ = 4180377600.

The previous prime is 20635987679. The next prime is 20635987681. The reversal of 20635987680 is 8678953602.

It is a happy number.

20635987680 is a `hidden beast` number, since 206 + 359 + 8 + 7 + 6 + 80 = 666.

It is an interprime number because it is at equal distance from previous prime (20635987679) and next prime (20635987681).

It is a super-2 number, since 2×20635987680² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20635987681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 182619304 + ... + 182619416.

It is an arithmetic number, because the mean of its divisors is an integer number (81041688).

Almost surely, 2^20635987680 is an apocalyptic number.

20635987680 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20635987680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (46680012288).

20635987680 is an abundant number, since it is smaller than the sum of its proper divisors (72724036896).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20635987680 is a wasteful number, since it uses less digits than its factorization.

20635987680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 222 (or 202 counting only the distinct ones).

The product of its (nonzero) digits is 4354560, while the sum is 54.

The spelling of 20635987680 in words is "twenty billion, six hundred thirty-five million, nine hundred eighty-seven thousand, six hundred eighty".