661753 has 4 divisors (see below), whose sum is σ = 664420. Its totient is φ = 659088.

The previous prime is 661741. The next prime is 661769. The reversal of 661753 is 357166.

661753 is nontrivially palindromic in base 15.

661753 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 131769 + 529984 = 363^2 + 728^2 .

It is a cyclic number.

It is not a de Polignac number, because 661753 - 2⁵ = 661721 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (661253) 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, 918 + ... + 1471.

It is an arithmetic number, because the mean of its divisors is an integer number (166105).

2⁶⁶¹⁷⁵³ is an apocalyptic number.

It is an amenable number.

661753 is a deficient number, since it is larger than the sum of its proper divisors (2667).

661753 is a wasteful number, since it uses less digits than its factorization.

661753 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2666.

The product of its digits is 3780, while the sum is 28.

The square root of 661753 is about 813.4820219280. The cubic root of 661753 is about 87.1428928475.

It can be divided in two parts, 6617 and 53, that added together give a triangular number (6670 = T₁₁₅).

The spelling of 661753 in words is "six hundred sixty-one thousand, seven hundred fifty-three".