391942692487 has 2 divisors, whose sum is σ = 391942692488. Its totient is φ = 391942692486.

The previous prime is 391942692469. The next prime is 391942692509. The reversal of 391942692487 is 784296249193.

It is a weak prime.

It is an emirp because it is prime and its reverse (784296249193) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-391942692487 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (391940692487) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 195971346243 + 195971346244.

It is an arithmetic number, because the mean of its divisors is an integer number (195971346244).

Almost surely, 2^391942692487 is an apocalyptic number.

391942692487 is a deficient number, since it is larger than the sum of its proper divisors (1).

391942692487 is an equidigital number, since it uses as much as digits as its factorization.

391942692487 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 47029248, while the sum is 64.

The spelling of 391942692487 in words is "three hundred ninety-one billion, nine hundred forty-two million, six hundred ninety-two thousand, four hundred eighty-seven".