76721831 has 4 divisors (see below), whose sum is σ = 78795432. Its totient is φ = 74648232.

The previous prime is 76721809. The next prime is 76721837. The reversal of 76721831 is 13812767.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 76721831 - 2¹⁰ = 76720807 is a prime.

It is a super-2 number, since 2×76721831² = 11772478703985122, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 76721791 and 76721800.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (76721837) 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, 1036745 + ... + 1036818.

It is an arithmetic number, because the mean of its divisors is an integer number (19698858).

Almost surely, 2^76721831 is an apocalyptic number.

76721831 is a deficient number, since it is larger than the sum of its proper divisors (2073601).

76721831 is a wasteful number, since it uses less digits than its factorization.

76721831 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2073600.

The product of its digits is 14112, while the sum is 35.

The square root of 76721831 is about 8759.0998966789. The cubic root of 76721831 is about 424.9191652491.

The spelling of 76721831 in words is "seventy-six million, seven hundred twenty-one thousand, eight hundred thirty-one".