21239086 has 32 divisors (see below), whose sum is σ = 37208160. Its totient is φ = 8985600.

The previous prime is 21239081. The next prime is 21239087. The reversal of 21239086 is 68093212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21239081) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 40506 + ... + 41026.

It is an arithmetic number, because the mean of its divisors is an integer number (1162755).

Almost surely, 2^21239086 is an apocalyptic number.

21239086 is a deficient number, since it is larger than the sum of its proper divisors (15969074).

21239086 is a wasteful number, since it uses less digits than its factorization.

21239086 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 660.

The product of its (nonzero) digits is 5184, while the sum is 31.

The square root of 21239086 is about 4608.5882871005. The cubic root of 21239086 is about 276.9354852425.

The spelling of 21239086 in words is "twenty-one million, two hundred thirty-nine thousand, eighty-six".