2516165978 has 4 divisors (see below), whose sum is σ = 3774248970. Its totient is φ = 1258082988.

The previous prime is 2516165923. The next prime is 2516165987. The reversal of 2516165978 is 8795616152.

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., 2511312769 + 4853209 = 50113^2 + 2203^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 629041493 + ... + 629041496.

Almost surely, 2^2516165978 is an apocalyptic number.

2516165978 is a deficient number, since it is larger than the sum of its proper divisors (1258082992).

2516165978 is a wasteful number, since it uses less digits than its factorization.

2516165978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1258082991.

The product of its digits is 907200, while the sum is 50.

The square root of 2516165978 is about 50161.3992827154. The cubic root of 2516165978 is about 1360.1279395931.

The spelling of 2516165978 in words is "two billion, five hundred sixteen million, one hundred sixty-five thousand, nine hundred seventy-eight".