2156278775 has 12 divisors (see below), whose sum is σ = 3055755312. Its totient is φ = 1478591040.

The previous prime is 2156278763. The next prime is 2156278781. The reversal of 2156278775 is 5778726512.

It is not a de Polignac number, because 2156278775 - 2¹⁰ = 2156277751 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6160622 + ... + 6160971.

It is an arithmetic number, because the mean of its divisors is an integer number (254646276).

Almost surely, 2^2156278775 is an apocalyptic number.

2156278775 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

2156278775 is a deficient number, since it is larger than the sum of its proper divisors (899476537).

2156278775 is a wasteful number, since it uses less digits than its factorization.

2156278775 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12321610 (or 12321605 counting only the distinct ones).

The product of its digits is 1646400, while the sum is 50.

The square root of 2156278775 is about 46435.7488902677. The cubic root of 2156278775 is about 1291.9180598907.

The spelling of 2156278775 in words is "two billion, one hundred fifty-six million, two hundred seventy-eight thousand, seven hundred seventy-five".