631690221 has 8 divisors (see below), whose sum is σ = 842436160. Its totient is φ = 421035552.

The previous prime is 631690219. The next prime is 631690223. The reversal of 631690221 is 122096136.

It is an interprime number because it is at equal distance from previous prime (631690219) and next prime (631690223).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 631690221 - 2¹ = 631690219 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 (631690223) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4585 + ... + 35838.

It is an arithmetic number, because the mean of its divisors is an integer number (105304520).

Almost surely, 2^631690221 is an apocalyptic number.

It is an amenable number.

631690221 is a deficient number, since it is larger than the sum of its proper divisors (210745939).

631690221 is a wasteful number, since it uses less digits than its factorization.

631690221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45635.

The product of its (nonzero) digits is 3888, while the sum is 30.

The square root of 631690221 is about 25133.4482512846. The cubic root of 631690221 is about 858.0278502270.

The spelling of 631690221 in words is "six hundred thirty-one million, six hundred ninety thousand, two hundred twenty-one".