2661257 has 4 divisors (see below), whose sum is σ = 2747136. Its totient is φ = 2575380.

The previous prime is 2661251. The next prime is 2661271. The reversal of 2661257 is 7521662.

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, and also an emirpimes, since its reverse is a distinct semiprime: 7521662 = 2 ⋅3760831.

It is a cyclic number.

It is not a de Polignac number, because 2661257 - 2¹⁸ = 2399113 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2661251) 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, 42893 + ... + 42954.

It is an arithmetic number, because the mean of its divisors is an integer number (686784).

2^2661257 is an apocalyptic number.

It is an amenable number.

2661257 is a deficient number, since it is larger than the sum of its proper divisors (85879).

2661257 is an equidigital number, since it uses as much as digits as its factorization.

2661257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85878.

The product of its digits is 5040, while the sum is 29.

The square root of 2661257 is about 1631.3359555898. The cubic root of 2661257 is about 138.5784200553.

The spelling of 2661257 in words is "two million, six hundred sixty-one thousand, two hundred fifty-seven".