21291634 has 24 divisors (see below), whose sum is σ = 39528000. Its totient is φ = 8422128.

The previous prime is 21291593. The next prime is 21291643. The reversal of 21291634 is 43619212.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2134 + ... + 6865.

It is an arithmetic number, because the mean of its divisors is an integer number (1647000).

Almost surely, 2^21291634 is an apocalyptic number.

21291634 is a deficient number, since it is larger than the sum of its proper divisors (18236366).

21291634 is a wasteful number, since it uses less digits than its factorization.

21291634 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9034 (or 9021 counting only the distinct ones).

The product of its digits is 2592, while the sum is 28.

The square root of 21291634 is about 4614.2858602388. The cubic root of 21291634 is about 277.1636874808.

The spelling of 21291634 in words is "twenty-one million, two hundred ninety-one thousand, six hundred thirty-four".