77234523921 has 81 divisors (see below), whose sum is σ = 120006773211. Its totient is φ = 49703826528.

The previous prime is 77234523901. The next prime is 77234523943. The reversal of 77234523921 is 12932543277.

The square root of 77234523921 is 277911.

It is a perfect power (a square), and thus also a powerful number.

77234523921 is a `hidden beast` number, since 7 + 7 + 2 + 34 + 523 + 92 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 43842078225 + 33392445696 = 209385^2 + 182736^2 .

It is a tau number, because it is divible by the number of its divisors (81).

It is not a de Polignac number, because 77234523921 - 2⁵ = 77234523889 is a prime.

It is not an unprimeable number, because it can be changed into a prime (77234523901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 1058007141 + ... + 1058007213.

Almost surely, 2^77234523921 is an apocalyptic number.

77234523921 is the 277911-st square number.

77234523921 is the 138956-th centered octagonal number.

It is an amenable number.

77234523921 is a deficient number, since it is larger than the sum of its proper divisors (42772249290).

77234523921 is an frugal number, since it uses more digits than its factorization.

77234523921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 264 (or 123 counting only the distinct ones).

The product of its digits is 635040, while the sum is 45.

The spelling of 77234523921 in words is "seventy-seven billion, two hundred thirty-four million, five hundred twenty-three thousand, nine hundred twenty-one".