21698912 has 48 divisors (see below), whose sum is σ = 45586800. Its totient is φ = 10137600.

The previous prime is 21698891. The next prime is 21698921. The reversal of 21698912 is 21989612.

It is a Harshad number since it is a multiple of its sum of digits (38).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 53912 + ... + 54312.

It is an arithmetic number, because the mean of its divisors is an integer number (949725).

Almost surely, 2^21698912 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 21698912, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22793400).

21698912 is an abundant number, since it is smaller than the sum of its proper divisors (23887888).

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

21698912 is a wasteful number, since it uses less digits than its factorization.

21698912 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 519 (or 511 counting only the distinct ones).

The product of its digits is 15552, while the sum is 38.

The square root of 21698912 is about 4658.2090979259. The cubic root of 21698912 is about 278.9197835532.

The spelling of 21698912 in words is "twenty-one million, six hundred ninety-eight thousand, nine hundred twelve".