76731021 has 6 divisors (see below), whose sum is σ = 110833710. Its totient is φ = 51154008.

The previous prime is 76731019. The next prime is 76731029. The reversal of 76731021 is 12013767.

It can be written as a sum of positive squares in only one way, i.e., 66096900 + 10634121 = 8130^2 + 3261^2 .

It is not a de Polignac number, because 76731021 - 2¹ = 76731019 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (76731029) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4262826 + ... + 4262843.

It is an arithmetic number, because the mean of its divisors is an integer number (18472285).

Almost surely, 2^76731021 is an apocalyptic number.

It is an amenable number.

76731021 is a deficient number, since it is larger than the sum of its proper divisors (34102689).

76731021 is a wasteful number, since it uses less digits than its factorization.

76731021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8525675 (or 8525672 counting only the distinct ones).

The product of its (nonzero) digits is 1764, while the sum is 27.

The square root of 76731021 is about 8759.6244782525. The cubic root of 76731021 is about 424.9361306559.

Adding to 76731021 its reverse (12013767), we get a palindrome (88744788).

The spelling of 76731021 in words is "seventy-six million, seven hundred thirty-one thousand, twenty-one".