2258721 has 6 divisors (see below), whose sum is σ = 3262610. Its totient is φ = 1505808.

The previous prime is 2258717. The next prime is 2258741. The reversal of 2258721 is 1278522.

It can be written as a sum of positive squares in only one way, i.e., 1527696 + 731025 = 1236^2 + 855^2 .

It is not a de Polignac number, because 2258721 - 2² = 2258717 is a prime.

It is a Duffinian number.

2258721 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2258741) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 125476 + ... + 125493.

2^2258721 is an apocalyptic number.

It is an amenable number.

2258721 is a deficient number, since it is larger than the sum of its proper divisors (1003889).

2258721 is a wasteful number, since it uses less digits than its factorization.

2258721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 250975 (or 250972 counting only the distinct ones).

The product of its digits is 2240, while the sum is 27.

The square root of 2258721 is about 1502.9041885629. The cubic root of 2258721 is about 131.2061513388.

The spelling of 2258721 in words is "two million, two hundred fifty-eight thousand, seven hundred twenty-one".