7656421 has 4 divisors (see below), whose sum is σ = 7667244. Its totient is φ = 7645600.

The previous prime is 7656413. The next prime is 7656431. The reversal of 7656421 is 1246567.

It is a happy number.

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 1476225 + 6180196 = 1215^2 + 2486^2 .

It is a cyclic number.

It is not a de Polignac number, because 7656421 - 2³ = 7656413 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7656431) 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, 4270 + ... + 5791.

It is an arithmetic number, because the mean of its divisors is an integer number (1916811).

Almost surely, 2^7656421 is an apocalyptic number.

It is an amenable number.

7656421 is a deficient number, since it is larger than the sum of its proper divisors (10823).

7656421 is a wasteful number, since it uses less digits than its factorization.

7656421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10822.

The product of its digits is 10080, while the sum is 31.

The square root of 7656421 is about 2767.0238524451. The cubic root of 7656421 is about 197.0948464068.

The spelling of 7656421 in words is "seven million, six hundred fifty-six thousand, four hundred twenty-one".