2162981681 has 4 divisors (see below), whose sum is σ = 2471979072. Its totient is φ = 1853984292.

The previous prime is 2162981677. The next prime is 2162981683. The reversal of 2162981681 is 1861892612.

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 2162981681 - 2² = 2162981677 is a prime.

It is a super-2 number, since 2×2162981681² = 9356979504683171522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2162981683) 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, 154498685 + ... + 154498698.

It is an arithmetic number, because the mean of its divisors is an integer number (617994768).

Almost surely, 2^2162981681 is an apocalyptic number.

It is an amenable number.

2162981681 is a deficient number, since it is larger than the sum of its proper divisors (308997391).

2162981681 is an equidigital number, since it uses as much as digits as its factorization.

2162981681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 308997390.

The product of its digits is 82944, while the sum is 44.

The square root of 2162981681 is about 46507.8668721755. The cubic root of 2162981681 is about 1293.2553402606.

The spelling of 2162981681 in words is "two billion, one hundred sixty-two million, nine hundred eighty-one thousand, six hundred eighty-one".