663731387 has 4 divisors (see below), whose sum is σ = 724070616. Its totient is φ = 603392160.

The previous prime is 663731363. The next prime is 663731417. The reversal of 663731387 is 783137366.

It is a happy number.

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 663731387 - 2¹² = 663727291 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (663731317) 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, 30169598 + ... + 30169619.

It is an arithmetic number, because the mean of its divisors is an integer number (181017654).

Almost surely, 2^663731387 is an apocalyptic number.

663731387 is a deficient number, since it is larger than the sum of its proper divisors (60339229).

663731387 is a wasteful number, since it uses less digits than its factorization.

663731387 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60339228.

The product of its digits is 381024, while the sum is 44.

The square root of 663731387 is about 25762.9848231916. The cubic root of 663731387 is about 872.2964769692.

The spelling of 663731387 in words is "six hundred sixty-three million, seven hundred thirty-one thousand, three hundred eighty-seven".