2165400931 has 4 divisors (see below), whose sum is σ = 2165751000. Its totient is φ = 2165050864.

The previous prime is 2165400899. The next prime is 2165400943. The reversal of 2165400931 is 1390045612.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 2165400931 - 2⁵ = 2165400899 is a prime.

It is a super-2 number, since 2×2165400931² = 9377922383951333522, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2165400893 and 2165400902.

It is not an unprimeable number, because it can be changed into a prime (2165400131) 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, 165586 + ... + 178183.

It is an arithmetic number, because the mean of its divisors is an integer number (541437750).

Almost surely, 2^2165400931 is an apocalyptic number.

2165400931 is a deficient number, since it is larger than the sum of its proper divisors (350069).

2165400931 is an equidigital number, since it uses as much as digits as its factorization.

2165400931 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 350068.

The product of its (nonzero) digits is 6480, while the sum is 31.

The square root of 2165400931 is about 46533.8686442466. The cubic root of 2165400931 is about 1293.7373203391.

The spelling of 2165400931 in words is "two billion, one hundred sixty-five million, four hundred thousand, nine hundred thirty-one".