7721864 has 8 divisors (see below), whose sum is σ = 14478510. Its totient is φ = 3860928.

The previous prime is 7721849. The next prime is 7721873. The reversal of 7721864 is 4681277.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 4972900 + 2748964 = 2230^2 + 1658^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 482609 + ... + 482624.

Almost surely, 2^7721864 is an apocalyptic number.

It is an amenable number.

7721864 is a deficient number, since it is larger than the sum of its proper divisors (6756646).

7721864 is a wasteful number, since it uses less digits than its factorization.

7721864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 965239 (or 965235 counting only the distinct ones).

The product of its digits is 18816, while the sum is 35.

The square root of 7721864 is about 2778.8242117845. The cubic root of 7721864 is about 197.6548078556.

The spelling of 7721864 in words is "seven million, seven hundred twenty-one thousand, eight hundred sixty-four".