2561320506 has 32 divisors (see below), whose sum is σ = 5260474368. Its totient is φ = 831055680.

The previous prime is 2561320501. The next prime is 2561320511. The reversal of 2561320506 is 6050231652.

It is an interprime number because it is at equal distance from previous prime (2561320501) and next prime (2561320511).

It is not an unprimeable number, because it can be changed into a prime (2561320501) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8676 + ... + 72096.

It is an arithmetic number, because the mean of its divisors is an integer number (164389824).

Almost surely, 2^2561320506 is an apocalyptic number.

2561320506 is an abundant number, since it is smaller than the sum of its proper divisors (2699153862).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

2561320506 is a wasteful number, since it uses less digits than its factorization.

2561320506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63606.

The product of its (nonzero) digits is 10800, while the sum is 30.

The square root of 2561320506 is about 50609.4902760342. The cubic root of 2561320506 is about 1368.2159287331.

The spelling of 2561320506 in words is "two billion, five hundred sixty-one million, three hundred twenty thousand, five hundred six".