21698908 has 24 divisors (see below), whose sum is σ = 47343744. Its totient is φ = 8454000.

The previous prime is 21698891. The next prime is 21698921. The reversal of 21698908 is 80989612.

It is a happy number.

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, 34918 + ... + 35533.

It is an arithmetic number, because the mean of its divisors is an integer number (1972656).

Almost surely, 2^21698908 is an apocalyptic number.

21698908 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21698908 is an abundant number, since it is smaller than the sum of its proper divisors (25644836).

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

21698908 is a wasteful number, since it uses less digits than its factorization.

21698908 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70473 (or 70471 counting only the distinct ones).

The product of its (nonzero) digits is 62208, while the sum is 43.

The square root of 21698908 is about 4658.2086685764. The cubic root of 21698908 is about 278.9197664144.

The spelling of 21698908 in words is "twenty-one million, six hundred ninety-eight thousand, nine hundred eight".