2515981665 has 16 divisors (see below), whose sum is σ = 4026787200. Its totient is φ = 1341451392.

The previous prime is 2515981649. The next prime is 2515981679. The reversal of 2515981665 is 5661895152.

It is not a de Polignac number, because 2515981665 - 2⁴ = 2515981649 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 29821 + ... + 76949.

It is an arithmetic number, because the mean of its divisors is an integer number (251674200).

Almost surely, 2^2515981665 is an apocalyptic number.

It is an amenable number.

2515981665 is a deficient number, since it is larger than the sum of its proper divisors (1510805535).

2515981665 is a wasteful number, since it uses less digits than its factorization.

2515981665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50696.

The product of its digits is 648000, while the sum is 48.

The square root of 2515981665 is about 50159.5620495235. The cubic root of 2515981665 is about 1360.0947282994.

It can be divided in two parts, 2515981 and 665, that added together give a triangular number (2516646 = T₂₂₄₃).

The spelling of 2515981665 in words is "two billion, five hundred fifteen million, nine hundred eighty-one thousand, six hundred sixty-five".