631380981 has 64 divisors (see below), whose sum is σ = 1103855616. Its totient is φ = 311256000.

The previous prime is 631380961. The next prime is 631380991. The reversal of 631380981 is 189083136.

It is not a de Polignac number, because 631380981 - 2¹³ = 631372789 is a prime.

It is a super-2 number, since 2×631380981² = 797283886337044722, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (631380931) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 801870 + ... + 802656.

It is an arithmetic number, because the mean of its divisors is an integer number (17247744).

Almost surely, 2^631380981 is an apocalyptic number.

It is an amenable number.

631380981 is a deficient number, since it is larger than the sum of its proper divisors (472474635).

631380981 is a wasteful number, since it uses less digits than its factorization.

631380981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 982.

The product of its (nonzero) digits is 31104, while the sum is 39.

The square root of 631380981 is about 25127.2955369256. The cubic root of 631380981 is about 857.8878133158.

The spelling of 631380981 in words is "six hundred thirty-one million, three hundred eighty thousand, nine hundred eighty-one".