7906421 has 4 divisors (see below), whose sum is σ = 7915200. Its totient is φ = 7897644.

The previous prime is 7906417. The next prime is 7906427. The reversal of 7906421 is 1246097.

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, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 1246097 = 43 ⋅28979.

It is a cyclic number.

It is not a de Polignac number, because 7906421 - 2² = 7906417 is a prime.

It is a super-2 number, since 2×7906421² = 125022986058482, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7906427) 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, 2861 + ... + 4898.

It is an arithmetic number, because the mean of its divisors is an integer number (1978800).

Almost surely, 2^7906421 is an apocalyptic number.

It is an amenable number.

7906421 is a deficient number, since it is larger than the sum of its proper divisors (8779).

7906421 is a wasteful number, since it uses less digits than its factorization.

7906421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8778.

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

The square root of 7906421 is about 2811.8358771450. The cubic root of 7906421 is about 199.2171144497.

The spelling of 7906421 in words is "seven million, nine hundred six thousand, four hundred twenty-one".