2501561987 has 4 divisors (see below), whose sum is σ = 2562575736. Its totient is φ = 2440548240.

The previous prime is 2501561977. The next prime is 2501561989. The reversal of 2501561987 is 7891651052.

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

It is a cyclic number.

It is not a de Polignac number, because 2501561987 - 2⁸ = 2501561731 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2501561989) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 30506813 + ... + 30506894.

It is an arithmetic number, because the mean of its divisors is an integer number (640643934).

Almost surely, 2^2501561987 is an apocalyptic number.

2501561987 is a deficient number, since it is larger than the sum of its proper divisors (61013749).

2501561987 is an equidigital number, since it uses as much as digits as its factorization.

2501561987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61013748.

The product of its (nonzero) digits is 151200, while the sum is 44.

The square root of 2501561987 is about 50015.6174309585. The cubic root of 2501561987 is about 1357.4914084519.

The spelling of 2501561987 in words is "two billion, five hundred one million, five hundred sixty-one thousand, nine hundred eighty-seven".