2509561978 has 64 divisors (see below), whose sum is σ = 4800902400. Its totient is φ = 955468800.

The previous prime is 2509561973. The next prime is 2509561979. The reversal of 2509561978 is 8791659052.

It is a Smith number, since the sum of its digits (52) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (2509561973) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2848098 + ... + 2848978.

It is an arithmetic number, because the mean of its divisors is an integer number (75014100).

Almost surely, 2^2509561978 is an apocalyptic number.

2509561978 is a deficient number, since it is larger than the sum of its proper divisors (2291340422).

2509561978 is a wasteful number, since it uses less digits than its factorization.

2509561978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1303.

The product of its (nonzero) digits is 1360800, while the sum is 52.

The square root of 2509561978 is about 50095.5285230129. The cubic root of 2509561978 is about 1358.9369536703.

The spelling of 2509561978 in words is "two billion, five hundred nine million, five hundred sixty-one thousand, nine hundred seventy-eight".