631138189 has 16 divisors (see below), whose sum is σ = 698941440. Its totient is φ = 565110000.

The previous prime is 631138187. The next prime is 631138199. The reversal of 631138189 is 981831136.

It is a cyclic number.

It is not a de Polignac number, because 631138189 - 2¹ = 631138187 is a prime.

It is a super-2 number, since 2×631138189² = 796670827228399442, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (631138187) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 547764 + ... + 548914.

It is an arithmetic number, because the mean of its divisors is an integer number (43683840).

Almost surely, 2^631138189 is an apocalyptic number.

It is an amenable number.

631138189 is a deficient number, since it is larger than the sum of its proper divisors (67803251).

631138189 is a wasteful number, since it uses less digits than its factorization.

631138189 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1872.

The product of its digits is 31104, while the sum is 40.

The square root of 631138189 is about 25122.4638321961. The cubic root of 631138189 is about 857.7778348145. Note that the first 3 decimals are identical.

The spelling of 631138189 in words is "six hundred thirty-one million, one hundred thirty-eight thousand, one hundred eighty-nine".