2775981 has 32 divisors (see below), whose sum is σ = 4354560. Its totient is φ = 1557504.

The previous prime is 2775959. The next prime is 2775989. The reversal of 2775981 is 1895772.

It is not a de Polignac number, because 2775981 - 2⁹ = 2775469 is a prime.

It is a super-2 number, since 2×2775981² = 15412141024722, which contains 22 as substring.

It is a Smith number, since the sum of its digits (39) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2775989) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 35100 + ... + 35178.

It is an arithmetic number, because the mean of its divisors is an integer number (136080).

2^2775981 is an apocalyptic number.

It is an amenable number.

2775981 is a deficient number, since it is larger than the sum of its proper divisors (1578579).

2775981 is a wasteful number, since it uses less digits than its factorization.

2775981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 165.

The product of its digits is 35280, while the sum is 39.

The square root of 2775981 is about 1666.1275461381. The cubic root of 2775981 is about 140.5417951248.

The spelling of 2775981 in words is "two million, seven hundred seventy-five thousand, nine hundred eighty-one".