21698583456 has 288 divisors, whose sum is σ = 65795393664. Its totient is φ = 6244761600.

The previous prime is 21698583449. The next prime is 21698583481. The reversal of 21698583456 is 65438589612.

It is an alternating number because its digits alternate between even and odd.

It is a junction number, because it is equal to n+sod(n) for n = 21698583396 and 21698583405.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 64387320 + ... + 64387656.

It is an arithmetic number, because the mean of its divisors is an integer number (228456228).

Almost surely, 2^21698583456 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 21698583456, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32897696832).

21698583456 is an abundant number, since it is smaller than the sum of its proper divisors (44096810208).

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

21698583456 is a wasteful number, since it uses less digits than its factorization.

21698583456 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 636 (or 617 counting only the distinct ones).

The product of its digits is 12441600, while the sum is 57.

The spelling of 21698583456 in words is "twenty-one billion, six hundred ninety-eight million, five hundred eighty-three thousand, four hundred fifty-six".