2551905 has 20 divisors (see below), whose sum is σ = 4575252. Its totient is φ = 1360800.

The previous prime is 2551903. The next prime is 2551933. The reversal of 2551905 is 5091552.

It can be written as a sum of positive squares in 2 ways, for example, as 1245456 + 1306449 = 1116^2 + 1143^2 .

It is not a de Polignac number, because 2551905 - 2¹ = 2551903 is a prime.

It is a Smith number, since the sum of its digits (27) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (2551903) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 2746 + ... + 3555.

2^2551905 is an apocalyptic number.

It is an amenable number.

2551905 is a deficient number, since it is larger than the sum of its proper divisors (2023347).

2551905 is an equidigital number, since it uses as much as digits as its factorization.

2551905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6318 (or 6309 counting only the distinct ones).

The product of its (nonzero) digits is 2250, while the sum is 27.

The square root of 2551905 is about 1597.4683095448. The cubic root of 2551905 is about 136.6537333256.

The spelling of 2551905 in words is "two million, five hundred fifty-one thousand, nine hundred five".