21386632 has 8 divisors (see below), whose sum is σ = 40099950. Its totient is φ = 10693312.

The previous prime is 21386623. The next prime is 21386639. The reversal of 21386632 is 23668312.

It can be written as a sum of positive squares in only one way, i.e., 21215236 + 171396 = 4606^2 + 414^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a junction number, because it is equal to n+sod(n) for n = 21386594 and 21386603.

It is not an unprimeable number, because it can be changed into a prime (21386639) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1336657 + ... + 1336672.

Almost surely, 2^21386632 is an apocalyptic number.

It is an amenable number.

21386632 is a deficient number, since it is larger than the sum of its proper divisors (18713318).

21386632 is a wasteful number, since it uses less digits than its factorization.

21386632 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2673335 (or 2673331 counting only the distinct ones).

The product of its digits is 10368, while the sum is 31.

The square root of 21386632 is about 4624.5683041772. The cubic root of 21386632 is about 277.5752878532.

The spelling of 21386632 in words is "twenty-one million, three hundred eighty-six thousand, six hundred thirty-two".