1397502731 has 4 divisors (see below), whose sum is σ = 1479708792. Its totient is φ = 1315296672.

The previous prime is 1397502719. The next prime is 1397502739. The reversal of 1397502731 is 1372057931.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1397502731 is a prime.

It is a super-2 number, since 2×1397502731² = 3906027766304916722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1397502739) 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, 41103005 + ... + 41103038.

It is an arithmetic number, because the mean of its divisors is an integer number (369927198).

Almost surely, 2^1397502731 is an apocalyptic number.

1397502731 is a deficient number, since it is larger than the sum of its proper divisors (82206061).

1397502731 is an equidigital number, since it uses as much as digits as its factorization.

1397502731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82206060.

The product of its (nonzero) digits is 39690, while the sum is 38.

The square root of 1397502731 is about 37383.1878121703. The cubic root of 1397502731 is about 1118.0233873327.

The spelling of 1397502731 in words is "one billion, three hundred ninety-seven million, five hundred two thousand, seven hundred thirty-one".