2906581981 has 4 divisors (see below), whose sum is σ = 3059560000. Its totient is φ = 2753603964.

The previous prime is 2906581949. The next prime is 2906582023. The reversal of 2906581981 is 1891856092.

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 2906581981 - 2⁵ = 2906581949 is a prime.

It is a super-2 number, since 2×2906581981² = 16896437624547768722, 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 (2906581081) 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, 76488981 + ... + 76489018.

It is an arithmetic number, because the mean of its divisors is an integer number (764890000).

Almost surely, 2^2906581981 is an apocalyptic number.

It is an amenable number.

2906581981 is a deficient number, since it is larger than the sum of its proper divisors (152978019).

2906581981 is a wasteful number, since it uses less digits than its factorization.

2906581981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 152978018.

The product of its (nonzero) digits is 311040, while the sum is 49.

The square root of 2906581981 is about 53912.7255942417. The cubic root of 2906581981 is about 1427.1212042370.

The spelling of 2906581981 in words is "two billion, nine hundred six million, five hundred eighty-one thousand, nine hundred eighty-one".