77139791 has 8 divisors (see below), whose sum is σ = 81498480. Its totient is φ = 72811008.

The previous prime is 77139773. The next prime is 77139809. The reversal of 77139791 is 19793177.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (77139773) and next prime (77139809).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 77139791 - 2¹⁰ = 77138767 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 (77139091) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2066 + ... + 12591.

It is an arithmetic number, because the mean of its divisors is an integer number (10187310).

Almost surely, 2^77139791 is an apocalyptic number.

77139791 is a deficient number, since it is larger than the sum of its proper divisors (4358689).

77139791 is a wasteful number, since it uses less digits than its factorization.

77139791 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14953.

The product of its digits is 83349, while the sum is 44.

The square root of 77139791 is about 8782.9261069418. The cubic root of 77139791 is about 425.6893835829.

The spelling of 77139791 in words is "seventy-seven million, one hundred thirty-nine thousand, seven hundred ninety-one".