21937390 has 8 divisors (see below), whose sum is σ = 39487320. Its totient is φ = 8774952.

The previous prime is 21937387. The next prime is 21937393. The reversal of 21937390 is 9373912.

It is an interprime number because it is at equal distance from previous prime (21937387) and next prime (21937393).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21937393) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1096860 + ... + 1096879.

It is an arithmetic number, because the mean of its divisors is an integer number (4935915).

Almost surely, 2^21937390 is an apocalyptic number.

21937390 is a deficient number, since it is larger than the sum of its proper divisors (17549930).

21937390 is a wasteful number, since it uses less digits than its factorization.

21937390 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2193746.

The product of its (nonzero) digits is 10206, while the sum is 34.

The square root of 21937390 is about 4683.7367560528. The cubic root of 21937390 is about 279.9378688674.

The spelling of 21937390 in words is "twenty-one million, nine hundred thirty-seven thousand, three hundred ninety".