2170981 has 4 divisors (see below), whose sum is σ = 2179264. Its totient is φ = 2162700.

The previous prime is 2170943. The next prime is 2171003. The reversal of 2170981 is 1890712.

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 2170981 - 2¹⁷ = 2039909 is a prime.

It is a super-2 number, since 2×2170981² = 9426317004722, which contains 22 as substring.

It is an Ulam number.

It is a Duffinian number.

It is a nialpdrome in base 12.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2170481) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3735 + ... + 4276.

It is an arithmetic number, because the mean of its divisors is an integer number (544816).

2^2170981 is an apocalyptic number.

It is an amenable number.

2170981 is a deficient number, since it is larger than the sum of its proper divisors (8283).

2170981 is an equidigital number, since it uses as much as digits as its factorization.

2170981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8282.

The product of its (nonzero) digits is 1008, while the sum is 28.

The square root of 2170981 is about 1473.4249217385. The cubic root of 2170981 is about 129.4847653799.

The spelling of 2170981 in words is "two million, one hundred seventy thousand, nine hundred eighty-one".