21339507 has 16 divisors (see below), whose sum is σ = 32769792. Its totient is φ = 12099360.

The previous prime is 21339503. The next prime is 21339509. The reversal of 21339507 is 70593312.

It is not a de Polignac number, because 21339507 - 2² = 21339503 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21339503) 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, 1128 + ... + 6629.

It is an arithmetic number, because the mean of its divisors is an integer number (2048112).

Almost surely, 2^21339507 is an apocalyptic number.

21339507 is a deficient number, since it is larger than the sum of its proper divisors (11430285).

21339507 is a wasteful number, since it uses less digits than its factorization.

21339507 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7898.

The product of its (nonzero) digits is 5670, while the sum is 30.

The square root of 21339507 is about 4619.4704241937. The cubic root of 21339507 is about 277.3712607936.

The spelling of 21339507 in words is "twenty-one million, three hundred thirty-nine thousand, five hundred seven".