21049624 has 8 divisors (see below), whose sum is σ = 39468060. Its totient is φ = 10524808.

The previous prime is 21049597. The next prime is 21049627. The reversal of 21049624 is 42694012.

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 = 21049592 and 21049601.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21049627) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1315594 + ... + 1315609.

Almost surely, 2^21049624 is an apocalyptic number.

It is an amenable number.

21049624 is a deficient number, since it is larger than the sum of its proper divisors (18418436).

21049624 is a wasteful number, since it uses less digits than its factorization.

21049624 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2631209 (or 2631205 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 28.

The square root of 21049624 is about 4587.9869223876. The cubic root of 21049624 is about 276.1095623269.

The spelling of 21049624 in words is "twenty-one million, forty-nine thousand, six hundred twenty-four".