3667634721 has 21 divisors (see below), whose sum is σ = 5501389249. Its totient is φ = 2443999716.

The previous prime is 3667634713. The next prime is 3667634741. The reversal of 3667634721 is 1274367663.

The square root of 3667634721 is 60561.

It is a perfect power (a square), and thus also a powerful number.

3667634721 is a `hidden beast` number, since 3 + 6 + 6 + 7 + 634 + 7 + 2 + 1 = 666.

3667634721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 3667634721 - 2³ = 3667634713 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3667634701) by changing a digit.

It is a polite number, since it can be written in 20 ways as a sum of consecutive naturals, for example, 1634026 + ... + 1636268.

Almost surely, 2^3667634721 is an apocalyptic number.

3667634721 is the 60561-st square number.

3667634721 is the 30281-st centered octagonal number.

It is an amenable number.

3667634721 is a deficient number, since it is larger than the sum of its proper divisors (1833754528).

3667634721 is an frugal number, since it uses more digits than its factorization.

3667634721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4504 (or 2246 counting only the distinct ones).

The product of its digits is 762048, while the sum is 45.

The cubic root of 3667634721 is about 1542.1573633102.

The spelling of 3667634721 in words is "three billion, six hundred sixty-seven million, six hundred thirty-four thousand, seven hundred twenty-one".