21907398 has 16 divisors (see below), whose sum is σ = 43868160. Its totient is φ = 7293576.

The previous prime is 21907397. The next prime is 21907429. The reversal of 21907398 is 89370912.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21907397) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4843 + ... + 8201.

It is an arithmetic number, because the mean of its divisors is an integer number (2741760).

Almost surely, 2^21907398 is an apocalyptic number.

21907398 is an abundant number, since it is smaller than the sum of its proper divisors (21960762).

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

21907398 is a wasteful number, since it uses less digits than its factorization.

21907398 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4451.

The product of its (nonzero) digits is 27216, while the sum is 39.

The square root of 21907398 is about 4680.5339439000. The cubic root of 21907398 is about 279.8102370683.

The spelling of 21907398 in words is "twenty-one million, nine hundred seven thousand, three hundred ninety-eight".