21012632 has 16 divisors (see below), whose sum is σ = 41472600. Its totient is φ = 9953280.

The previous prime is 21012599. The next prime is 21012647. The reversal of 21012632 is 23621012.

It is a self number, because there is not a number n which added to its sum of digits gives 21012632.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 68969 + ... + 69272.

Almost surely, 2^21012632 is an apocalyptic number.

It is an amenable number.

21012632 is a deficient number, since it is larger than the sum of its proper divisors (20459968).

21012632 is a wasteful number, since it uses less digits than its factorization.

21012632 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 138266 (or 138262 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 17.

The square root of 21012632 is about 4583.9537519482. The cubic root of 21012632 is about 275.9477251694.

Adding to 21012632 its reverse (23621012), we get a palindrome (44633644).

The spelling of 21012632 in words is "twenty-one million, twelve thousand, six hundred thirty-two".