2656991 has 2 divisors, whose sum is σ = 2656992. Its totient is φ = 2656990.

The previous prime is 2656987. The next prime is 2656993. The reversal of 2656991 is 1996562.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 2656991 - 2² = 2656987 is a prime.

Together with 2656993, it forms a pair of twin primes.

It is a Chen prime.

It is a plaindrome in base 16.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2656993) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1328495 + 1328496.

It is an arithmetic number, because the mean of its divisors is an integer number (1328496).

2^2656991 is an apocalyptic number.

2656991 is a deficient number, since it is larger than the sum of its proper divisors (1).

2656991 is an equidigital number, since it uses as much as digits as its factorization.

2656991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 29160, while the sum is 38.

The square root of 2656991 is about 1630.0279138714. The cubic root of 2656991 is about 138.5043332977.

The spelling of 2656991 in words is "two million, six hundred fifty-six thousand, nine hundred ninety-one".