20979544 has 8 divisors (see below), whose sum is σ = 39336660. Its totient is φ = 10489768.

The previous prime is 20979533. The next prime is 20979551. The reversal of 20979544 is 44597902.

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 = 20979497 and 20979506.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1311214 + ... + 1311229.

Almost surely, 2^20979544 is an apocalyptic number.

It is an amenable number.

20979544 is a deficient number, since it is larger than the sum of its proper divisors (18357116).

20979544 is a wasteful number, since it uses less digits than its factorization.

20979544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2622449 (or 2622445 counting only the distinct ones).

The product of its (nonzero) digits is 90720, while the sum is 40.

The square root of 20979544 is about 4580.3432185809. The cubic root of 20979544 is about 275.8028067052.

The spelling of 20979544 in words is "twenty million, nine hundred seventy-nine thousand, five hundred forty-four".