18977965 has 4 divisors (see below), whose sum is σ = 22773564. Its totient is φ = 15182368.

The previous prime is 18977963. The next prime is 18978019. The reversal of 18977965 is 56977981.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 56977981 = 701 ⋅81281.

It can be written as a sum of positive squares in 2 ways, for example, as 4247721 + 14730244 = 2061^2 + 3838^2 .

It is a cyclic number.

It is not a de Polignac number, because 18977965 - 2¹ = 18977963 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18977963) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1897792 + ... + 1897801.

It is an arithmetic number, because the mean of its divisors is an integer number (5693391).

Almost surely, 2^18977965 is an apocalyptic number.

It is an amenable number.

18977965 is a deficient number, since it is larger than the sum of its proper divisors (3795599).

18977965 is an equidigital number, since it uses as much as digits as its factorization.

18977965 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3795598.

The product of its digits is 952560, while the sum is 52.

The square root of 18977965 is about 4356.3706224333. The cubic root of 18977965 is about 266.7369701790.

The spelling of 18977965 in words is "eighteen million, nine hundred seventy-seven thousand, nine hundred sixty-five".