2155760064778 has 4 divisors (see below), whose sum is σ = 3233640097170. Its totient is φ = 1077880032388.

The previous prime is 2155760064763. The next prime is 2155760064947. The reversal of 2155760064778 is 8774600675512.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 1122949254249 + 1032810810529 = 1059693^2 + 1016273^2 .

It is a Smith number, since the sum of its digits (58) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 538940016193 + ... + 538940016196.

Almost surely, 2^{2155760064778} is an apocalyptic number.

2155760064778 is a deficient number, since it is larger than the sum of its proper divisors (1077880032392).

2155760064778 is a wasteful number, since it uses less digits than its factorization.

2155760064778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1077880032391.

The product of its (nonzero) digits is 19756800, while the sum is 58.

The spelling of 2155760064778 in words is "two trillion, one hundred fifty-five billion, seven hundred sixty million, sixty-four thousand, seven hundred seventy-eight".