631977139 has 4 divisors (see below), whose sum is σ = 632373480. Its totient is φ = 631580800.

The previous prime is 631977127. The next prime is 631977173. The reversal of 631977139 is 931779136.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 631977139 - 2⁹ = 631976627 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (631977109) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 195769 + ... + 198970.

It is an arithmetic number, because the mean of its divisors is an integer number (158093370).

Almost surely, 2^631977139 is an apocalyptic number.

631977139 is a deficient number, since it is larger than the sum of its proper divisors (396341).

631977139 is a wasteful number, since it uses less digits than its factorization.

631977139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 396340.

The product of its digits is 214326, while the sum is 46.

The square root of 631977139 is about 25139.1554949644. The cubic root of 631977139 is about 858.1577379278.

The spelling of 631977139 in words is "six hundred thirty-one million, nine hundred seventy-seven thousand, one hundred thirty-nine".