77551321 has 4 divisors (see below), whose sum is σ = 77569552. Its totient is φ = 77533092.

The previous prime is 77551301. The next prime is 77551333. The reversal of 77551321 is 12315577.

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 a cyclic number.

It is not a de Polignac number, because 77551321 - 2⁵ = 77551289 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (77551301) 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, 1030 + ... + 12496.

It is an arithmetic number, because the mean of its divisors is an integer number (19392388).

Almost surely, 2^77551321 is an apocalyptic number.

It is an amenable number.

77551321 is a deficient number, since it is larger than the sum of its proper divisors (18231).

77551321 is a wasteful number, since it uses less digits than its factorization.

77551321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18230.

The product of its digits is 7350, while the sum is 31.

The square root of 77551321 is about 8806.3227853628. The cubic root of 77551321 is about 426.4450391812.

Adding to 77551321 its reverse (12315577), we get a palindrome (89866898).

The spelling of 77551321 in words is "seventy-seven million, five hundred fifty-one thousand, three hundred twenty-one".