21479646 has 16 divisors (see below), whose sum is σ = 43038864. Its totient is φ = 7146624.

The previous prime is 21479639. The next prime is 21479657. The reversal of 21479646 is 64697412.

It is a happy number.

It is a super-2 number, since 2×21479646² = 922750384570632, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 540 + ... + 6576.

It is an arithmetic number, because the mean of its divisors is an integer number (2689929).

Almost surely, 2^21479646 is an apocalyptic number.

21479646 is an abundant number, since it is smaller than the sum of its proper divisors (21559218).

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

21479646 is a wasteful number, since it uses less digits than its factorization.

21479646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6635.

The product of its digits is 72576, while the sum is 39.

The square root of 21479646 is about 4634.6138997763. The cubic root of 21479646 is about 277.9771128269.

The spelling of 21479646 in words is "twenty-one million, four hundred seventy-nine thousand, six hundred forty-six".