977566710221 has 4 divisors (see below), whose sum is σ = 977931885372. Its totient is φ = 977201535072.

The previous prime is 977566710167. The next prime is 977566710223. The reversal of 977566710221 is 122017665779.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 56494634596 + 921072075625 = 237686^2 + 959725^2 .

It is a cyclic number.

It is not a de Polignac number, because 977566710221 - 2²⁶ = 977499601357 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 (977566710223) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 182583560 + ... + 182588913.

It is an arithmetic number, because the mean of its divisors is an integer number (244482971343).

Almost surely, 2^977566710221 is an apocalyptic number.

It is an amenable number.

977566710221 is a deficient number, since it is larger than the sum of its proper divisors (365175151).

977566710221 is a wasteful number, since it uses less digits than its factorization.

977566710221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 365175150.

The product of its (nonzero) digits is 2222640, while the sum is 53.

The spelling of 977566710221 in words is "nine hundred seventy-seven billion, five hundred sixty-six million, seven hundred ten thousand, two hundred twenty-one".