2523981 has 4 divisors (see below), whose sum is σ = 3365312. Its totient is φ = 1682652.

The previous prime is 2523967. The next prime is 2523991. The reversal of 2523981 is 1893252.

It is a happy number.

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 not a de Polignac number, because 2523981 - 2⁵ = 2523949 is a prime.

It is a super-2 number, since 2×2523981² = 12740960176722, which contains 22 as substring.

It is a D-number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2523901) 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, 420661 + ... + 420666.

It is an arithmetic number, because the mean of its divisors is an integer number (841328).

2^2523981 is an apocalyptic number.

It is an amenable number.

2523981 is a deficient number, since it is larger than the sum of its proper divisors (841331).

2523981 is an equidigital number, since it uses as much as digits as its factorization.

2523981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 841330.

The product of its digits is 4320, while the sum is 30.

The square root of 2523981 is about 1588.7041889540. The cubic root of 2523981 is about 136.1534635876.

The spelling of 2523981 in words is "two million, five hundred twenty-three thousand, nine hundred eighty-one".