661875 has 20 divisors (see below), whose sum is σ = 1105896. Its totient is φ = 352000.

The previous prime is 661873. The next prime is 661877. The reversal of 661875 is 578166.

661875 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (661873) and next prime (661877).

It is not a de Polignac number, because 661875 - 2¹ = 661873 is a prime.

It is not an unprimeable number, because it can be changed into a prime (661873) 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, 1699 + ... + 2051.

2⁶⁶¹⁸⁷⁵ is an apocalyptic number.

661875 is a deficient number, since it is larger than the sum of its proper divisors (444021).

661875 is an equidigital number, since it uses as much as digits as its factorization.

661875 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 376 (or 361 counting only the distinct ones).

The product of its digits is 10080, while the sum is 33.

The square root of 661875 is about 813.5570047636. The cubic root of 661875 is about 87.1482477053.

The spelling of 661875 in words is "six hundred sixty-one thousand, eight hundred seventy-five".