76904721 has 10 divisors (see below), whose sum is σ = 114882482. Its totient is φ = 51269760.

The previous prime is 76904717. The next prime is 76904741. The reversal of 76904721 is 12740967.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 68558400 + 8346321 = 8280^2 + 2889^2 .

It is not a de Polignac number, because 76904721 - 2² = 76904717 is a prime.

It is a super-2 number, since 2×76904721² = 11828672224175682, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (76904701) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 474640 + ... + 474801.

Almost surely, 2^76904721 is an apocalyptic number.

It is an amenable number.

76904721 is a deficient number, since it is larger than the sum of its proper divisors (37977761).

76904721 is an equidigital number, since it uses as much as digits as its factorization.

76904721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 949453 (or 949444 counting only the distinct ones).

The product of its (nonzero) digits is 21168, while the sum is 36.

The square root of 76904721 is about 8769.5336820153. The cubic root of 76904721 is about 425.2565390034.

The spelling of 76904721 in words is "seventy-six million, nine hundred four thousand, seven hundred twenty-one".