21138310 has 16 divisors (see below), whose sum is σ = 40287456. Its totient is φ = 7957888.

The previous prime is 21138307. The next prime is 21138319. The reversal of 21138310 is 1383112.

It is a super-2 number, since 2×21138310² = 893656299312200, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21138319) 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, 62002 + ... + 62341.

It is an arithmetic number, because the mean of its divisors is an integer number (2517966).

Almost surely, 2^21138310 is an apocalyptic number.

21138310 is a deficient number, since it is larger than the sum of its proper divisors (19149146).

21138310 is a wasteful number, since it uses less digits than its factorization.

21138310 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 124367.

The product of its (nonzero) digits is 144, while the sum is 19.

The square root of 21138310 is about 4597.6417868294. The cubic root of 21138310 is about 276.4967860830.

The spelling of 21138310 in words is "twenty-one million, one hundred thirty-eight thousand, three hundred ten".