661253 has 2 divisors, whose sum is σ = 661254. Its totient is φ = 661252.

The previous prime is 661237. The next prime is 661259. The reversal of 661253 is 352166.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 611524 + 49729 = 782^2 + 223^2 .

It is a cyclic number.

It is not a de Polignac number, because 661253 - 2⁴ = 661237 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (661259) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330626 + 330627.

It is an arithmetic number, because the mean of its divisors is an integer number (330627).

2⁶⁶¹²⁵³ is an apocalyptic number.

It is an amenable number.

661253 is a deficient number, since it is larger than the sum of its proper divisors (1).

661253 is an equidigital number, since it uses as much as digits as its factorization.

661253 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1080, while the sum is 23.

The square root of 661253 is about 813.1746429888. The cubic root of 661253 is about 87.1209398304.

The spelling of 661253 in words is "six hundred sixty-one thousand, two hundred fifty-three".