2158981 has 4 divisors (see below), whose sum is σ = 2355264. Its totient is φ = 1962700.

The previous prime is 2158979. The next prime is 2158993. The reversal of 2158981 is 1898512.

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 2158981 - 2¹ = 2158979 is a prime.

It is a super-2 number, since 2×2158981² = 9322397916722, 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 (2158921) 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, 98125 + ... + 98146.

It is an arithmetic number, because the mean of its divisors is an integer number (588816).

2^2158981 is an apocalyptic number.

It is an amenable number.

2158981 is a deficient number, since it is larger than the sum of its proper divisors (196283).

2158981 is a wasteful number, since it uses less digits than its factorization.

2158981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 196282.

The product of its digits is 5760, while the sum is 34.

The square root of 2158981 is about 1469.3471339340. The cubic root of 2158981 is about 129.2457507142.

The spelling of 2158981 in words is "two million, one hundred fifty-eight thousand, nine hundred eighty-one".