631978101 has 12 divisors (see below), whose sum is σ = 913288428. Its totient is φ = 421119744.

The previous prime is 631978099. The next prime is 631978147. The reversal of 631978101 is 101879136.

631978101 is a `hidden beast` number, since 631 + 9 + 7 + 8 + 10 + 1 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 417384900 + 214593201 = 20430^2 + 14649^2 .

It is not a de Polignac number, because 631978101 - 2¹ = 631978099 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (631978001) 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, 5011 + ... + 35903.

It is an arithmetic number, because the mean of its divisors is an integer number (76107369).

Almost surely, 2^631978101 is an apocalyptic number.

It is an amenable number.

631978101 is a deficient number, since it is larger than the sum of its proper divisors (281310327).

631978101 is a wasteful number, since it uses less digits than its factorization.

631978101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33172 (or 33169 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 36.

The square root of 631978101 is about 25139.1746284559. The cubic root of 631978101 is about 858.1581733588.

The spelling of 631978101 in words is "six hundred thirty-one million, nine hundred seventy-eight thousand, one hundred one".