77456813 has 4 divisors (see below), whose sum is σ = 88522080. Its totient is φ = 66391548.

The previous prime is 77456791. The next prime is 77456849. The reversal of 77456813 is 31865477.

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, and also an emirpimes, since its reverse is a distinct semiprime: 31865477 = 7 ⋅4552211.

It is a cyclic number.

It is not a de Polignac number, because 77456813 - 2¹⁶ = 77391277 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 (77456213) 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, 5532623 + ... + 5532636.

It is an arithmetic number, because the mean of its divisors is an integer number (22130520).

Almost surely, 2^77456813 is an apocalyptic number.

It is an amenable number.

77456813 is a deficient number, since it is larger than the sum of its proper divisors (11065267).

77456813 is a wasteful number, since it uses less digits than its factorization.

77456813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11065266.

The product of its digits is 141120, while the sum is 41.

The square root of 77456813 is about 8800.9552322461. The cubic root of 77456813 is about 426.2717395310.

The spelling of 77456813 in words is "seventy-seven million, four hundred fifty-six thousand, eight hundred thirteen".