1872661 has 4 divisors (see below), whose sum is σ = 2140192. Its totient is φ = 1605132.

The previous prime is 1872631. The next prime is 1872667. The reversal of 1872661 is 1662781.

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.

It is a cyclic number.

It is not a de Polignac number, because 1872661 - 2⁹ = 1872149 is a prime.

It is a Duffinian number.

1872661 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1872667) 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, 133755 + ... + 133768.

It is an arithmetic number, because the mean of its divisors is an integer number (535048).

2^1872661 is an apocalyptic number.

It is an amenable number.

1872661 is a deficient number, since it is larger than the sum of its proper divisors (267531).

1872661 is an equidigital number, since it uses as much as digits as its factorization.

1872661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 267530.

The product of its digits is 4032, while the sum is 31.

The square root of 1872661 is about 1368.4520451956. The cubic root of 1872661 is about 123.2593070911.

The spelling of 1872661 in words is "one million, eight hundred seventy-two thousand, six hundred sixty-one".