21602139 has 8 divisors (see below), whose sum is σ = 31018512. Its totient is φ = 13293600.

The previous prime is 21602137. The next prime is 21602143. The reversal of 21602139 is 93120612.

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

It is not a de Polignac number, because 21602139 - 2¹ = 21602137 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21602137) 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, 276912 + ... + 276989.

It is an arithmetic number, because the mean of its divisors is an integer number (3877314).

Almost surely, 2^21602139 is an apocalyptic number.

21602139 is a deficient number, since it is larger than the sum of its proper divisors (9416373).

21602139 is a wasteful number, since it uses less digits than its factorization.

21602139 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 553917.

The product of its (nonzero) digits is 648, while the sum is 24.

The square root of 21602139 is about 4647.8101295126. The cubic root of 21602139 is about 278.5045226379.

The spelling of 21602139 in words is "twenty-one million, six hundred two thousand, one hundred thirty-nine".