77647231 has 4 divisors (see below), whose sum is σ = 77805864. Its totient is φ = 77488600.

The previous prime is 77647189. The next prime is 77647267. The reversal of 77647231 is 13274677.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13274677 = 13 ⋅1021129.

It is a cyclic number.

It is not a de Polignac number, because 77647231 - 2⁹ = 77646719 is a prime.

It is a super-2 number, since 2×77647231² = 12058184963934722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77647631) 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, 78580 + ... + 79561.

It is an arithmetic number, because the mean of its divisors is an integer number (19451466).

Almost surely, 2^77647231 is an apocalyptic number.

77647231 is a deficient number, since it is larger than the sum of its proper divisors (158633).

77647231 is a wasteful number, since it uses less digits than its factorization.

77647231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 158632.

The product of its digits is 49392, while the sum is 37.

The square root of 77647231 is about 8811.7666219663. The cubic root of 77647231 is about 426.6207658005.

The spelling of 77647231 in words is "seventy-seven million, six hundred forty-seven thousand, two hundred thirty-one".