21937870 has 16 divisors (see below), whose sum is σ = 40452048. Its totient is φ = 8560960.

The previous prime is 21937859. The next prime is 21937873. The reversal of 21937870 is 7873912.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21937873) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 26344 + ... + 27163.

It is an arithmetic number, because the mean of its divisors is an integer number (2528253).

Almost surely, 2^21937870 is an apocalyptic number.

21937870 is a deficient number, since it is larger than the sum of its proper divisors (18514178).

21937870 is a wasteful number, since it uses less digits than its factorization.

21937870 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53555.

The product of its (nonzero) digits is 21168, while the sum is 37.

The square root of 21937870 is about 4683.7879969102. The cubic root of 21937870 is about 279.9399105748.

The spelling of 21937870 in words is "twenty-one million, nine hundred thirty-seven thousand, eight hundred seventy".