2891688391 has 2 divisors, whose sum is σ = 2891688392. Its totient is φ = 2891688390.

The previous prime is 2891688383. The next prime is 2891688407. The reversal of 2891688391 is 1938861982.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 2891688391 - 2³ = 2891688383 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2891688311) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1445844195 + 1445844196.

It is an arithmetic number, because the mean of its divisors is an integer number (1445844196).

Almost surely, 2^2891688391 is an apocalyptic number.

2891688391 is a deficient number, since it is larger than the sum of its proper divisors (1).

2891688391 is an equidigital number, since it uses as much as digits as its factorization.

2891688391 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1492992, while the sum is 55.

The square root of 2891688391 is about 53774.4213450968. The cubic root of 2891688391 is about 1424.6794626944.

The spelling of 2891688391 in words is "two billion, eight hundred ninety-one million, six hundred eighty-eight thousand, three hundred ninety-one".