661935 has 8 divisors (see below), whose sum is σ = 1059120. Its totient is φ = 353024.

The previous prime is 661931. The next prime is 661939. The reversal of 661935 is 539166.

It is a happy number.

661935 is nontrivially palindromic in base 14.

It is an interprime number because it is at equal distance from previous prime (661931) and next prime (661939).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 661935 - 2² = 661931 is a prime.

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 22050 + ... + 22079.

It is an arithmetic number, because the mean of its divisors is an integer number (132390).

2⁶⁶¹⁹³⁵ is an apocalyptic number.

661935 is a deficient number, since it is larger than the sum of its proper divisors (397185).

661935 is a wasteful number, since it uses less digits than its factorization.

661935 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44137.

The product of its digits is 4860, while the sum is 30.

The square root of 661935 is about 813.5938790330. The cubic root of 661935 is about 87.1508810006.

It can be divided in two parts, 661 and 935, that added together give a triangular number (1596 = T₅₆).

The spelling of 661935 in words is "six hundred sixty-one thousand, nine hundred thirty-five".