18979577 has 4 divisors (see below), whose sum is σ = 19804800. Its totient is φ = 18154356.

The previous prime is 18979561. The next prime is 18979579. The reversal of 18979577 is 77597981.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 77597981 = 131 ⋅592351.

It is a cyclic number.

It is not a de Polignac number, because 18979577 - 2⁴ = 18979561 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18979579) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 412577 + ... + 412622.

It is an arithmetic number, because the mean of its divisors is an integer number (4951200).

Almost surely, 2^18979577 is an apocalyptic number.

It is an amenable number.

18979577 is a deficient number, since it is larger than the sum of its proper divisors (825223).

18979577 is an equidigital number, since it uses as much as digits as its factorization.

18979577 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 825222.

The product of its digits is 1111320, while the sum is 53.

The square root of 18979577 is about 4356.5556349024. Note that the first 3 decimals coincide. The cubic root of 18979577 is about 266.7445222325.

The spelling of 18979577 in words is "eighteen million, nine hundred seventy-nine thousand, five hundred seventy-seven".