20685974694528 has 256 divisors, whose sum is σ = 65156580195840. Its totient is φ = 5732207554560.

The previous prime is 20685974694479. The next prime is 20685974694533. The reversal of 20685974694528 is 82549647958602.

It is a self number, because there is not a number n which added to its sum of digits gives 20685974694528.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4115251 + ... + 7635917.

It is an arithmetic number, because the mean of its divisors is an integer number (254517891390).

Almost surely, 2^{20685974694528} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20685974694528, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32578290097920).

20685974694528 is an abundant number, since it is smaller than the sum of its proper divisors (44470605501312).

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

20685974694528 is a wasteful number, since it uses less digits than its factorization.

20685974694528 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3520815 (or 3520803 counting only the distinct ones).

The product of its (nonzero) digits is 2090188800, while the sum is 75.

The spelling of 20685974694528 in words is "twenty trillion, six hundred eighty-five billion, nine hundred seventy-four million, six hundred ninety-four thousand, five hundred twenty-eight".