631020389 has 4 divisors (see below), whose sum is σ = 631155840. Its totient is φ = 630884940.

The previous prime is 631020359. The next prime is 631020421. The reversal of 631020389 is 983020136.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 631020389 - 2⁸ = 631020133 is a prime.

It is a super-2 number, since 2×631020389² = 796373462667422642, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (631020359) 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, 60479 + ... + 70140.

It is an arithmetic number, because the mean of its divisors is an integer number (157788960).

Almost surely, 2^631020389 is an apocalyptic number.

It is an amenable number.

631020389 is a deficient number, since it is larger than the sum of its proper divisors (135451).

631020389 is a wasteful number, since it uses less digits than its factorization.

631020389 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 135450.

The product of its (nonzero) digits is 7776, while the sum is 32.

The square root of 631020389 is about 25120.1192075197. The cubic root of 631020389 is about 857.7244642965.

The spelling of 631020389 in words is "six hundred thirty-one million, twenty thousand, three hundred eighty-nine".