20643166740 has 192 divisors, whose sum is σ = 70085836800. Its totient is φ = 4434683904.

The previous prime is 20643166727. The next prime is 20643166741. The reversal of 20643166740 is 4766134602.

It is a happy number.

It is a super-2 number, since 2×20643166740² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20643166741) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1003276 + ... + 1023644.

It is an arithmetic number, because the mean of its divisors is an integer number (365030400).

Almost surely, 2^20643166740 is an apocalyptic number.

20643166740 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 20643166740, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35042918400).

20643166740 is an abundant number, since it is smaller than the sum of its proper divisors (49442670060).

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

20643166740 is a wasteful number, since it uses less digits than its factorization.

20643166740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20534 (or 20532 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 39.

The spelling of 20643166740 in words is "twenty billion, six hundred forty-three million, one hundred sixty-six thousand, seven hundred forty".