20984624640 has 960 divisors, whose sum is σ = 88654325760. Its totient is φ = 4658135040.

The previous prime is 20984624623. The next prime is 20984624681. The reversal of 20984624640 is 4642648902.

20984624640 is a `hidden beast` number, since 20 + 98 + 462 + 46 + 40 = 666.

It is a tau number, because it is divible by the number of its divisors (960).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 265628121 + ... + 265628199.

It is an arithmetic number, because the mean of its divisors is an integer number (92348256).

Almost surely, 2^20984624640 is an apocalyptic number.

20984624640 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 20984624640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44327162880).

20984624640 is an abundant number, since it is smaller than the sum of its proper divisors (67669701120).

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

20984624640 is an frugal number, since it uses more digits than its factorization.

20984624640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 185 (or 157 counting only the distinct ones).

The product of its (nonzero) digits is 663552, while the sum is 45.

The spelling of 20984624640 in words is "twenty billion, nine hundred eighty-four million, six hundred twenty-four thousand, six hundred forty".