7904430921 has 4 divisors (see below), whose sum is σ = 10539241232. Its totient is φ = 5269620612.

The previous prime is 7904430917. The next prime is 7904430943. The reversal of 7904430921 is 1290344097.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 7904430921 - 2² = 7904430917 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 7904430921.

It is not an unprimeable number, because it can be changed into a prime (7904430991) 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, 1317405151 + ... + 1317405156.

It is an arithmetic number, because the mean of its divisors is an integer number (2634810308).

Almost surely, 2^7904430921 is an apocalyptic number.

It is an amenable number.

7904430921 is a deficient number, since it is larger than the sum of its proper divisors (2634810311).

7904430921 is a wasteful number, since it uses less digits than its factorization.

7904430921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2634810310.

The product of its (nonzero) digits is 54432, while the sum is 39.

The square root of 7904430921 is about 88906.8665570888. The cubic root of 7904430921 is about 1992.0039845548.

The spelling of 7904430921 in words is "seven billion, nine hundred four million, four hundred thirty thousand, nine hundred twenty-one".