21696856473600 has 4320 divisors, whose sum is σ = 106485934464000. Its totient is φ = 4242486067200.

The previous prime is 21696856473559. The next prime is 21696856473671. The reversal of 21696856473600 is 637465869612.

21696856473600 is a `hidden beast` number, since 2 + 1 + 6 + 9 + 6 + 8 + 564 + 7 + 3 + 60 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (4320).

It is a Harshad number since it is a multiple of its sum of digits (63).

It is an unprimeable number.

It is a polite number, since it can be written in 287 ways as a sum of consecutive naturals, for example, 145616486326 + ... + 145616486474.

It is a 1-persistent number, because it is pandigital, but 2⋅21696856473600 = 43393712947200 is not.

Almost surely, 2^{21696856473600} is an apocalyptic number.

21696856473600 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 21696856473600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (53242967232000).

21696856473600 is an abundant number, since it is smaller than the sum of its proper divisors (84789077990400).

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

21696856473600 is a wasteful number, since it uses less digits than its factorization.

21696856473600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 239 (or 196 counting only the distinct ones).

The product of its (nonzero) digits is 78382080, while the sum is 63.

The spelling of 21696856473600 in words is "twenty-one trillion, six hundred ninety-six billion, eight hundred fifty-six million, four hundred seventy-three thousand, six hundred".