8631751221 has 12 divisors (see below), whose sum is σ = 12468948960. Its totient is φ = 5754102120.

The previous prime is 8631751159. The next prime is 8631751223. The reversal of 8631751221 is 1221571368.

8631751221 is a `hidden beast` number, since 8 + 631 + 7 + 5 + 12 + 2 + 1 = 666.

It is not a de Polignac number, because 8631751221 - 2¹⁷ = 8631620149 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8631751223) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 168090 + ... + 213348.

It is an arithmetic number, because the mean of its divisors is an integer number (1039079080).

Almost surely, 2^8631751221 is an apocalyptic number.

It is an amenable number.

8631751221 is a deficient number, since it is larger than the sum of its proper divisors (3837197739).

8631751221 is a wasteful number, since it uses less digits than its factorization.

8631751221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66456 (or 66453 counting only the distinct ones).

The product of its digits is 20160, while the sum is 36.

The square root of 8631751221 is about 92907.2183471231. The cubic root of 8631751221 is about 2051.3179089331.

The spelling of 8631751221 in words is "eight billion, six hundred thirty-one million, seven hundred fifty-one thousand, two hundred twenty-one".