20561624 has 8 divisors (see below), whose sum is σ = 38553060. Its totient is φ = 10280808.

The previous prime is 20561621. The next prime is 20561633. The reversal of 20561624 is 42616502.

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 = 20561593 and 20561602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20561621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1285094 + ... + 1285109.

Almost surely, 2^20561624 is an apocalyptic number.

It is an amenable number.

20561624 is a deficient number, since it is larger than the sum of its proper divisors (17991436).

20561624 is a wasteful number, since it uses less digits than its factorization.

20561624 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2570209 (or 2570205 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 26.

The square root of 20561624 is about 4534.4926948888. The cubic root of 20561624 is about 273.9591464122.

The spelling of 20561624 in words is "twenty million, five hundred sixty-one thousand, six hundred twenty-four".