7721631 has 6 divisors (see below), whose sum is σ = 11153480. Its totient is φ = 5147748.

The previous prime is 7721611. The next prime is 7721671. The reversal of 7721631 is 1361277.

7721631 is a `hidden beast` number, since 7 + 7 + 21 + 631 = 666.

7721631 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 7721631 - 2²² = 3527327 is a prime.

It is a super-2 number, since 2×7721631² = 119247170600322, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 7721595 and 7721604.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7721611) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 428971 + ... + 428988.

Almost surely, 2^7721631 is an apocalyptic number.

7721631 is a deficient number, since it is larger than the sum of its proper divisors (3431849).

7721631 is a wasteful number, since it uses less digits than its factorization.

7721631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 857965 (or 857962 counting only the distinct ones).

The product of its digits is 1764, while the sum is 27.

The square root of 7721631 is about 2778.7822872618. The cubic root of 7721631 is about 197.6528198194.

The spelling of 7721631 in words is "seven million, seven hundred twenty-one thousand, six hundred thirty-one".