2891639 has 2 divisors, whose sum is σ = 2891640. Its totient is φ = 2891638.

The previous prime is 2891599. The next prime is 2891657. The reversal of 2891639 is 9361982.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 2891639 - 2²⁰ = 1843063 is a prime.

It is a super-2 number, since 2×2891639² = 16723152212642, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2896639) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1445819 + 1445820.

It is an arithmetic number, because the mean of its divisors is an integer number (1445820).

2^2891639 is an apocalyptic number.

2891639 is a deficient number, since it is larger than the sum of its proper divisors (1).

2891639 is an equidigital number, since it uses as much as digits as its factorization.

2891639 is an evil number, because the sum of its binary digits is even.

The product of its digits is 23328, while the sum is 38.

The square root of 2891639 is about 1700.4819904956. The cubic root of 2891639 is about 142.4671351315.

The spelling of 2891639 in words is "two million, eight hundred ninety-one thousand, six hundred thirty-nine".