16391431787 has 2 divisors, whose sum is σ = 16391431788. Its totient is φ = 16391431786.

The previous prime is 16391431783. The next prime is 16391431789. The reversal of 16391431787 is 78713419361.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 16391431787 - 2² = 16391431783 is a prime.

Together with 16391431789, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (16391431783) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8195715893 + 8195715894.

It is an arithmetic number, because the mean of its divisors is an integer number (8195715894).

Almost surely, 2^16391431787 is an apocalyptic number.

16391431787 is a deficient number, since it is larger than the sum of its proper divisors (1).

16391431787 is an equidigital number, since it uses as much as digits as its factorization.

16391431787 is an evil number, because the sum of its binary digits is even.

The product of its digits is 762048, while the sum is 50.

The spelling of 16391431787 in words is "sixteen billion, three hundred ninety-one million, four hundred thirty-one thousand, seven hundred eighty-seven".