397187639 has 2 divisors, whose sum is σ = 397187640. Its totient is φ = 397187638.

The previous prime is 397187633. The next prime is 397187663. The reversal of 397187639 is 936781793.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-397187639 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (397187633) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 198593819 + 198593820.

It is an arithmetic number, because the mean of its divisors is an integer number (198593820).

Almost surely, 2^397187639 is an apocalyptic number.

397187639 is a deficient number, since it is larger than the sum of its proper divisors (1).

397187639 is an equidigital number, since it uses as much as digits as its factorization.

397187639 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1714608, while the sum is 53.

The square root of 397187639 is about 19929.5669546531. The cubic root of 397187639 is about 735.0754324297.

The spelling of 397187639 in words is "three hundred ninety-seven million, one hundred eighty-seven thousand, six hundred thirty-nine".