2156253420691 has 2 divisors, whose sum is σ = 2156253420692. Its totient is φ = 2156253420690.

The previous prime is 2156253420689. The next prime is 2156253420709. The reversal of 2156253420691 is 1960243526512.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 2156253420691 - 2¹ = 2156253420689 is a prime.

Together with 2156253420689, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (2156253421691) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1078126710345 + 1078126710346.

It is an arithmetic number, because the mean of its divisors is an integer number (1078126710346).

Almost surely, 2^{2156253420691} is an apocalyptic number.

2156253420691 is a deficient number, since it is larger than the sum of its proper divisors (1).

2156253420691 is an equidigital number, since it uses as much as digits as its factorization.

2156253420691 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 777600, while the sum is 46.

The spelling of 2156253420691 in words is "two trillion, one hundred fifty-six billion, two hundred fifty-three million, four hundred twenty thousand, six hundred ninety-one".