2635981 has 4 divisors (see below), whose sum is σ = 2675392. Its totient is φ = 2596572.

The previous prime is 2635979. The next prime is 2635987. The reversal of 2635981 is 1895362.

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 2635981 - 2¹ = 2635979 is a prime.

It is a super-2 number, since 2×2635981² = 13896791664722, 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 (2635987) 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, 19605 + ... + 19738.

It is an arithmetic number, because the mean of its divisors is an integer number (668848).

2^2635981 is an apocalyptic number.

It is an amenable number.

2635981 is a deficient number, since it is larger than the sum of its proper divisors (39411).

2635981 is an equidigital number, since it uses as much as digits as its factorization.

2635981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39410.

The product of its digits is 12960, while the sum is 34.

The square root of 2635981 is about 1623.5704481174. The cubic root of 2635981 is about 138.1382951652.

The spelling of 2635981 in words is "two million, six hundred thirty-five thousand, nine hundred eighty-one".