7913921 has 4 divisors (see below), whose sum is σ = 7926192. Its totient is φ = 7901652.

The previous prime is 7913911. The next prime is 7913923. The reversal of 7913921 is 1293197.

It is a happy number.

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 a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-7913921 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (7913923) 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, 5111 + ... + 6476.

It is an arithmetic number, because the mean of its divisors is an integer number (1981548).

Almost surely, 2^7913921 is an apocalyptic number.

It is an amenable number.

7913921 is a deficient number, since it is larger than the sum of its proper divisors (12271).

7913921 is a wasteful number, since it uses less digits than its factorization.

7913921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12270.

The product of its digits is 3402, while the sum is 32.

The square root of 7913921 is about 2813.1692092727. The cubic root of 7913921 is about 199.2800867337.

The spelling of 7913921 in words is "seven million, nine hundred thirteen thousand, nine hundred twenty-one".