2157678923 has 2 divisors, whose sum is σ = 2157678924. Its totient is φ = 2157678922.

The previous prime is 2157678899. The next prime is 2157678977. The reversal of 2157678923 is 3298767512.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 2157678923 - 2⁸ = 2157678667 is a prime.

It is not a weakly prime, because it can be changed into another prime (2157678223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1078839461 + 1078839462.

It is an arithmetic number, because the mean of its divisors is an integer number (1078839462).

Almost surely, 2^2157678923 is an apocalyptic number.

2157678923 is a deficient number, since it is larger than the sum of its proper divisors (1).

2157678923 is an equidigital number, since it uses as much as digits as its factorization.

2157678923 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1270080, while the sum is 50.

The square root of 2157678923 is about 46450.8226299600. The cubic root of 2157678923 is about 1292.1976287368.

The spelling of 2157678923 in words is "two billion, one hundred fifty-seven million, six hundred seventy-eight thousand, nine hundred twenty-three".