977989 has 4 divisors (see below), whose sum is σ = 989856. Its totient is φ = 966124.

The previous prime is 977971. The next prime is 978001. The reversal of 977989 is 989779.

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: 989779 = 7 ⋅141397.

It is a cyclic number.

It is not a de Polignac number, because 977989 - 2⁷ = 977861 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (971989) 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, 5809 + ... + 5974.

It is an arithmetic number, because the mean of its divisors is an integer number (247464).

2⁹⁷⁷⁹⁸⁹ is an apocalyptic number.

It is an amenable number.

977989 is a deficient number, since it is larger than the sum of its proper divisors (11867).

977989 is a wasteful number, since it uses less digits than its factorization.

977989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11866.

The product of its digits is 285768, while the sum is 49.

The square root of 977989 is about 988.9332636735. The cubic root of 977989 is about 99.2608500343.

The spelling of 977989 in words is "nine hundred seventy-seven thousand, nine hundred eighty-nine".