20177979 has 8 divisors (see below), whose sum is σ = 27082752. Its totient is φ = 13362600.

The previous prime is 20177977. The next prime is 20177999. The reversal of 20177979 is 97977102.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20177979 - 2¹ = 20177977 is a prime.

It is a zygodrome in base 7.

It is a self number, because there is not a number n which added to its sum of digits gives 20177979.

It is not an unprimeable number, because it can be changed into a prime (20177977) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21819 + ... + 22724.

It is an arithmetic number, because the mean of its divisors is an integer number (3385344).

Almost surely, 2^20177979 is an apocalyptic number.

20177979 is a deficient number, since it is larger than the sum of its proper divisors (6904773).

20177979 is a wasteful number, since it uses less digits than its factorization.

20177979 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44697.

The product of its (nonzero) digits is 55566, while the sum is 42.

The square root of 20177979 is about 4491.9905387256. The cubic root of 20177979 is about 272.2445671941.

The spelling of 20177979 in words is "twenty million, one hundred seventy-seven thousand, nine hundred seventy-nine".