2251561 has 16 divisors (see below), whose sum is σ = 2587648. Its totient is φ = 1944000.

The previous prime is 2251559. The next prime is 2251573. The reversal of 2251561 is 1651522.

It is a 5-Lehmer number, since φ(2251561) divides (2251561-1)⁵.

It is a cyclic number.

It is not a de Polignac number, because 2251561 - 2¹ = 2251559 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2251511) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14836 + ... + 14986.

It is an arithmetic number, because the mean of its divisors is an integer number (161728).

2^2251561 is an apocalyptic number.

It is an amenable number.

2251561 is a deficient number, since it is larger than the sum of its proper divisors (336087).

2251561 is a wasteful number, since it uses less digits than its factorization.

2251561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 232.

The product of its digits is 600, while the sum is 22.

The square root of 2251561 is about 1500.5202431157. The cubic root of 2251561 is about 131.0673662408.

The spelling of 2251561 in words is "two million, two hundred fifty-one thousand, five hundred sixty-one".