77764521 has 4 divisors (see below), whose sum is σ = 103686032. Its totient is φ = 51843012.

The previous prime is 77764517. The next prime is 77764543. The reversal of 77764521 is 12546777.

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.

It is not a de Polignac number, because 77764521 - 2² = 77764517 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 77764521.

It is not an unprimeable number, because it can be changed into a prime (77764571) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12960751 + ... + 12960756.

It is an arithmetic number, because the mean of its divisors is an integer number (25921508).

Almost surely, 2^77764521 is an apocalyptic number.

It is an amenable number.

77764521 is a deficient number, since it is larger than the sum of its proper divisors (25921511).

77764521 is a wasteful number, since it uses less digits than its factorization.

77764521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25921510.

The product of its digits is 82320, while the sum is 39.

The square root of 77764521 is about 8818.4194161993. The cubic root of 77764521 is about 426.8354683510.

The spelling of 77764521 in words is "seventy-seven million, seven hundred sixty-four thousand, five hundred twenty-one".