2180396681 has 4 divisors (see below), whose sum is σ = 2180619792. Its totient is φ = 2180173572.

The previous prime is 2180396641. The next prime is 2180396719. The reversal of 2180396681 is 1866930812.

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 2180396681 - 2²² = 2176202377 is a prime.

It is a super-2 number, since 2×2180396681² = 9508259373031631522, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (2180396641) 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, 96191 + ... + 116676.

It is an arithmetic number, because the mean of its divisors is an integer number (545154948).

Almost surely, 2^2180396681 is an apocalyptic number.

It is an amenable number.

2180396681 is a deficient number, since it is larger than the sum of its proper divisors (223111).

2180396681 is a wasteful number, since it uses less digits than its factorization.

2180396681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 223110.

The product of its (nonzero) digits is 124416, while the sum is 44.

The square root of 2180396681 is about 46694.7179132715. The cubic root of 2180396681 is about 1296.7168992625.

The spelling of 2180396681 in words is "two billion, one hundred eighty million, three hundred ninety-six thousand, six hundred eighty-one".