76720136257 has 8 divisors (see below), whose sum is σ = 76880069000. Its totient is φ = 76560297984.

The previous prime is 76720136203. The next prime is 76720136261. The reversal of 76720136257 is 75263102767.

It is a happy number.

It is a Cunningham number, because it is equal to 276984²+1.

It can be written as a sum of positive squares in 4 ways, for example, as 4741148736 + 71978987521 = 68856^2 + 268289^2 .

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 76720136257 - 2²⁷ = 76585918529 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (76720133257) 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, 1737469 + ... + 1781077.

It is an arithmetic number, because the mean of its divisors is an integer number (9610008625).

Almost surely, 2^76720136257 is an apocalyptic number.

It is an amenable number.

76720136257 is a deficient number, since it is larger than the sum of its proper divisors (159932743).

76720136257 is a wasteful number, since it uses less digits than its factorization.

76720136257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47235.

The product of its (nonzero) digits is 740880, while the sum is 46.

The spelling of 76720136257 in words is "seventy-six billion, seven hundred twenty million, one hundred thirty-six thousand, two hundred fifty-seven".