20540979 has 16 divisors (see below), whose sum is σ = 30592000. Its totient is φ = 13621608.

The previous prime is 20540977. The next prime is 20540999. The reversal of 20540979 is 97904502.

20540979 is a `hidden beast` number, since 20 + 540 + 97 + 9 = 666.

It is not a de Polignac number, because 20540979 - 2¹ = 20540977 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20540977) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3462 + ... + 7284.

It is an arithmetic number, because the mean of its divisors is an integer number (1912000).

Almost surely, 2^20540979 is an apocalyptic number.

20540979 is a deficient number, since it is larger than the sum of its proper divisors (10051021).

20540979 is a wasteful number, since it uses less digits than its factorization.

20540979 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4031 (or 4025 counting only the distinct ones).

The product of its (nonzero) digits is 22680, while the sum is 36.

The square root of 20540979 is about 4532.2156833055. The cubic root of 20540979 is about 273.8674256971.

The spelling of 20540979 in words is "twenty million, five hundred forty thousand, nine hundred seventy-nine".