2155942278 has 256 divisors, whose sum is σ = 6096384000. Its totient is φ = 562222080.

The previous prime is 2155942267. The next prime is 2155942279. The reversal of 2155942278 is 8722495512.

2155942278 is a `hidden beast` number, since 2 + 1 + 559 + 4 + 22 + 78 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2155942279) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 12909751 + ... + 12909917.

It is an arithmetic number, because the mean of its divisors is an integer number (23814000).

Almost surely, 2^2155942278 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2155942278, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3048192000).

2155942278 is an abundant number, since it is smaller than the sum of its proper divisors (3940441722).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

2155942278 is a wasteful number, since it uses less digits than its factorization.

2155942278 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 257 (or 237 counting only the distinct ones).

The product of its digits is 403200, while the sum is 45.

The square root of 2155942278 is about 46432.1254951784. The cubic root of 2155942278 is about 1291.8508531869.

The spelling of 2155942278 in words is "two billion, one hundred fifty-five million, nine hundred forty-two thousand, two hundred seventy-eight".