20685974400 has 960 divisors, whose sum is σ = 94058875680. Its totient is φ = 4359536640.

The previous prime is 20685974399. The next prime is 20685974411. The reversal of 20685974400 is 447958602.

It is a happy number.

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 pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 23586762 + ... + 23587638.

Almost surely, 2^20685974400 is an apocalyptic number.

20685974400 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 20685974400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (47029437840).

20685974400 is an abundant number, since it is smaller than the sum of its proper divisors (73372901280).

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

20685974400 is a wasteful number, since it uses less digits than its factorization.

20685974400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 933 (or 907 counting only the distinct ones).

The product of its (nonzero) digits is 483840, while the sum is 45.

The spelling of 20685974400 in words is "twenty billion, six hundred eighty-five million, nine hundred seventy-four thousand, four hundred".