84977989 has 2 divisors, whose sum is σ = 84977990. Its totient is φ = 84977988.

The previous prime is 84977947. The next prime is 84977993. The reversal of 84977989 is 98977948.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 48580900 + 36397089 = 6970^2 + 6033^2 .

It is a cyclic number.

It is not a de Polignac number, because 84977989 - 2¹¹ = 84975941 is a prime.

It is a super-2 number, since 2×84977989² = 14442517228968242, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (84977999) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42488994 + 42488995.

It is an arithmetic number, because the mean of its divisors is an integer number (42488995).

Almost surely, 2^84977989 is an apocalyptic number.

It is an amenable number.

84977989 is a deficient number, since it is larger than the sum of its proper divisors (1).

84977989 is an equidigital number, since it uses as much as digits as its factorization.

84977989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9144576, while the sum is 61.

The square root of 84977989 is about 9218.3506659272. The cubic root of 84977989 is about 439.6450115402.

The spelling of 84977989 in words is "eighty-four million, nine hundred seventy-seven thousand, nine hundred eighty-nine".