2979581981 has 4 divisors (see below), whose sum is σ = 2999314464. Its totient is φ = 2959849500.

The previous prime is 2979581977. The next prime is 2979581987. The reversal of 2979581981 is 1891859792.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 2979581981 - 2² = 2979581977 is a prime.

It is a super-2 number, since 2×2979581981² = 17755817562999768722, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2979581981.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2979581987) 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, 9866015 + ... + 9866316.

It is an arithmetic number, because the mean of its divisors is an integer number (749828616).

Almost surely, 2^2979581981 is an apocalyptic number.

It is an amenable number.

2979581981 is a deficient number, since it is larger than the sum of its proper divisors (19732483).

2979581981 is a wasteful number, since it uses less digits than its factorization.

2979581981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19732482.

The product of its digits is 3265920, while the sum is 59.

The square root of 2979581981 is about 54585.5473637482. The cubic root of 2979581981 is about 1438.9701324883.

The spelling of 2979581981 in words is "two billion, nine hundred seventy-nine million, five hundred eighty-one thousand, nine hundred eighty-one".