76904021 has 4 divisors (see below), whose sum is σ = 77110572. Its totient is φ = 76697472.

The previous prime is 76904017. The next prime is 76904029. The reversal of 76904021 is 12040967.

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

It can be written as a sum of positive squares in 2 ways, for example, as 50268100 + 26635921 = 7090^2 + 5161^2 .

It is a cyclic number.

It is not a de Polignac number, because 76904021 - 2² = 76904017 is a prime.

It is a super-4 number, since 4×76904021⁴ (a number of 33 digits) contains 4444 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (76904029) 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, 102716 + ... + 103461.

It is an arithmetic number, because the mean of its divisors is an integer number (19277643).

Almost surely, 2^76904021 is an apocalyptic number.

It is an amenable number.

76904021 is a deficient number, since it is larger than the sum of its proper divisors (206551).

76904021 is a wasteful number, since it uses less digits than its factorization.

76904021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 206550.

The product of its (nonzero) digits is 3024, while the sum is 29.

The square root of 76904021 is about 8769.4937710224. The cubic root of 76904021 is about 425.2552487468.

Adding to 76904021 its reverse (12040967), we get a palindrome (88944988).

It can be divided in two parts, 7690 and 4021, that added together give a palindrome (11711).

The spelling of 76904021 in words is "seventy-six million, nine hundred four thousand, twenty-one".