2609081981 has 24 divisors (see below), whose sum is σ = 2998947840. Its totient is φ = 2263900320.

The previous prime is 2609081963. The next prime is 2609082017. The reversal of 2609081981 is 1891809062.

It is a de Polignac number, because none of the positive numbers 2^k-2609081981 is a prime.

It is a super-2 number, since 2×2609081981² = 13614617567157768722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2609081911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2039300 + ... + 2040578.

It is an arithmetic number, because the mean of its divisors is an integer number (124956160).

Almost surely, 2^2609081981 is an apocalyptic number.

It is an amenable number.

2609081981 is a deficient number, since it is larger than the sum of its proper divisors (389865859).

2609081981 is a wasteful number, since it uses less digits than its factorization.

2609081981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2057 (or 2046 counting only the distinct ones).

The product of its (nonzero) digits is 62208, while the sum is 44.

The square root of 2609081981 is about 51079.1736522822. The cubic root of 2609081981 is about 1376.6680768928.

The spelling of 2609081981 in words is "two billion, six hundred nine million, eighty-one thousand, nine hundred eighty-one".