2156478887 has 2 divisors, whose sum is σ = 2156478888. Its totient is φ = 2156478886.

The previous prime is 2156478871. The next prime is 2156478959. The reversal of 2156478887 is 7888746512.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 2156478887 - 2⁴ = 2156478871 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2156478847) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1078239443 + 1078239444.

It is an arithmetic number, because the mean of its divisors is an integer number (1078239444).

Almost surely, 2^2156478887 is an apocalyptic number.

2156478887 is a deficient number, since it is larger than the sum of its proper divisors (1).

2156478887 is an equidigital number, since it uses as much as digits as its factorization.

2156478887 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6021120, while the sum is 56.

The square root of 2156478887 is about 46437.9035594847. The cubic root of 2156478887 is about 1291.9580238497.

The spelling of 2156478887 in words is "two billion, one hundred fifty-six million, four hundred seventy-eight thousand, eight hundred eighty-seven".