20979560 has 64 divisors (see below), whose sum is σ = 55710720. Its totient is φ = 6958080.

The previous prime is 20979559. The next prime is 20979583. The reversal of 20979560 is 6597902.

20979560 = T₁₆₆₅ + T₁₆₆₆ + ... + T₁₆₇₉.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7472 + ... + 9888.

It is an arithmetic number, because the mean of its divisors is an integer number (870480).

Almost surely, 2^20979560 is an apocalyptic number.

20979560 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20979560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27855360).

20979560 is an abundant number, since it is smaller than the sum of its proper divisors (34731160).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20979560 is a wasteful number, since it uses less digits than its factorization.

20979560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2466 (or 2462 counting only the distinct ones).

The product of its (nonzero) digits is 34020, while the sum is 38.

The square root of 20979560 is about 4580.3449651746. The cubic root of 20979560 is about 275.8028768186.

The spelling of 20979560 in words is "twenty million, nine hundred seventy-nine thousand, five hundred sixty".