661245 has 16 divisors (see below), whose sum is σ = 1139712. Its totient is φ = 325440.

The previous prime is 661237. The next prime is 661253. The reversal of 661245 is 542166.

It is an interprime number because it is at equal distance from previous prime (661237) and next prime (661253).

It is not a de Polignac number, because 661245 - 2³ = 661237 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1501 + ... + 1890.

It is an arithmetic number, because the mean of its divisors is an integer number (71232).

2⁶⁶¹²⁴⁵ is an apocalyptic number.

661245 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

It is an amenable number.

661245 is a deficient number, since it is larger than the sum of its proper divisors (478467).

661245 is a wasteful number, since it uses less digits than its factorization.

661245 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3412.

The product of its digits is 1440, while the sum is 24.

The square root of 661245 is about 813.1697239814. The cubic root of 661245 is about 87.1205884922.

The spelling of 661245 in words is "six hundred sixty-one thousand, two hundred forty-five".