21399486 has 32 divisors (see below), whose sum is σ = 44648448. Its totient is φ = 6829920.

The previous prime is 21399479. The next prime is 21399493. The reversal of 21399486 is 68499312.

It is an interprime number because it is at equal distance from previous prime (21399479) and next prime (21399493).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18600 + ... + 19716.

It is an arithmetic number, because the mean of its divisors is an integer number (1395264).

Almost surely, 2^21399486 is an apocalyptic number.

21399486 is an abundant number, since it is smaller than the sum of its proper divisors (23248962).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21399486 is a wasteful number, since it uses less digits than its factorization.

21399486 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1256.

The product of its digits is 93312, while the sum is 42.

The square root of 21399486 is about 4625.9578467600. The cubic root of 21399486 is about 277.6308870421.

It can be divided in two parts, 213 and 99486, that added together give a palindrome (99699).

The spelling of 21399486 in words is "twenty-one million, three hundred ninety-nine thousand, four hundred eighty-six".