2638981 has 4 divisors (see below), whose sum is σ = 2645964. Its totient is φ = 2632000.

The previous prime is 2638973. The next prime is 2639041. The reversal of 2638981 is 1898362.

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

It can be written as a sum of positive squares in 2 ways, for example, as 1846881 + 792100 = 1359^2 + 890^2 .

It is a cyclic number.

It is not a de Polignac number, because 2638981 - 2³ = 2638973 is a prime.

It is a super-2 number, since 2×2638981² = 13928441436722, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2638981.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2638901) 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, 2890 + ... + 3691.

It is an arithmetic number, because the mean of its divisors is an integer number (661491).

2^2638981 is an apocalyptic number.

It is an amenable number.

2638981 is a deficient number, since it is larger than the sum of its proper divisors (6983).

2638981 is an equidigital number, since it uses as much as digits as its factorization.

2638981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6982.

The product of its digits is 20736, while the sum is 37.

The square root of 2638981 is about 1624.4940750892. The cubic root of 2638981 is about 138.1906801874.

The spelling of 2638981 in words is "two million, six hundred thirty-eight thousand, nine hundred eighty-one".