2172981 has 8 divisors (see below), whose sum is σ = 2910880. Its totient is φ = 1441872.

The previous prime is 2172979. The next prime is 2172983. The reversal of 2172981 is 1892712.

It is an interprime number because it is at equal distance from previous prime (2172979) and next prime (2172983).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 2172981 - 2¹ = 2172979 is a prime.

It is a super-2 number, since 2×2172981² = 9443692852722, 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 (2172983) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 895 + ... + 2268.

It is an arithmetic number, because the mean of its divisors is an integer number (363860).

2^2172981 is an apocalyptic number.

It is an amenable number.

2172981 is a deficient number, since it is larger than the sum of its proper divisors (737899).

2172981 is a wasteful number, since it uses less digits than its factorization.

2172981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3395.

The product of its digits is 2016, while the sum is 30.

The square root of 2172981 is about 1474.1034563422. The cubic root of 2172981 is about 129.5245154662.

The spelling of 2172981 in words is "two million, one hundred seventy-two thousand, nine hundred eighty-one".