2156851 has 2 divisors, whose sum is σ = 2156852. Its totient is φ = 2156850.

The previous prime is 2156849. The next prime is 2156857. The reversal of 2156851 is 1586512.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 2156851 - 2¹ = 2156849 is a prime.

Together with 2156849, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (2156857) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1078425 + 1078426.

It is an arithmetic number, because the mean of its divisors is an integer number (1078426).

2^2156851 is an apocalyptic number.

2156851 is a deficient number, since it is larger than the sum of its proper divisors (1).

2156851 is an equidigital number, since it uses as much as digits as its factorization.

2156851 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2400, while the sum is 28.

The square root of 2156851 is about 1468.6221433711. The cubic root of 2156851 is about 129.2032331205.

The spelling of 2156851 in words is "two million, one hundred fifty-six thousand, eight hundred fifty-one".