21938070 has 64 divisors (see below), whose sum is σ = 65650176. Its totient is φ = 4558080.

The previous prime is 21938057. The next prime is 21938083. The reversal of 21938070 is 7083912.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21938057) and next prime (21938083).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2439 + ... + 7058.

It is an arithmetic number, because the mean of its divisors is an integer number (1025784).

Almost surely, 2^21938070 is an apocalyptic number.

21938070 is an abundant number, since it is smaller than the sum of its proper divisors (43712106).

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

21938070 is a wasteful number, since it uses less digits than its factorization.

21938070 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9525.

The product of its (nonzero) digits is 3024, while the sum is 30.

The square root of 21938070 is about 4683.8093471020. The cubic root of 21938070 is about 279.9407612775.

The spelling of 21938070 in words is "twenty-one million, nine hundred thirty-eight thousand, seventy".