977628661 has 2 divisors, whose sum is σ = 977628662. Its totient is φ = 977628660.

The previous prime is 977628581. The next prime is 977628677. The reversal of 977628661 is 166826779.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 934463761 + 43164900 = 30569^2 + 6570^2 .

It is a cyclic number.

It is not a de Polignac number, because 977628661 - 2¹⁵ = 977595893 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 977628599 and 977628608.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (977625661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 488814330 + 488814331.

It is an arithmetic number, because the mean of its divisors is an integer number (488814331).

Almost surely, 2^977628661 is an apocalyptic number.

It is an amenable number.

977628661 is a deficient number, since it is larger than the sum of its proper divisors (1).

977628661 is an equidigital number, since it uses as much as digits as its factorization.

977628661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1524096, while the sum is 52.

The square root of 977628661 is about 31267.0539226196. The cubic root of 977628661 is about 992.4865768540.

The spelling of 977628661 in words is "nine hundred seventy-seven million, six hundred twenty-eight thousand, six hundred sixty-one".