21697132 has 24 divisors (see below), whose sum is σ = 39085200. Its totient is φ = 10534656.

The previous prime is 21697129. The next prime is 21697147. The reversal of 21697132 is 23179612.

It is a junction number, because it is equal to n+sod(n) for n = 21697094 and 21697103.

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 7 ways as a sum of consecutive naturals, for example, 20488 + ... + 21520.

It is an arithmetic number, because the mean of its divisors is an integer number (1628550).

Almost surely, 2^21697132 is an apocalyptic number.

It is an amenable number.

21697132 is a deficient number, since it is larger than the sum of its proper divisors (17388068).

21697132 is a wasteful number, since it uses less digits than its factorization.

21697132 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1185 (or 1183 counting only the distinct ones).

The product of its digits is 4536, while the sum is 31.

The square root of 21697132 is about 4658.0180334559. The cubic root of 21697132 is about 278.9121565841.

The spelling of 21697132 in words is "twenty-one million, six hundred ninety-seven thousand, one hundred thirty-two".