661735 has 4 divisors (see below), whose sum is σ = 794088. Its totient is φ = 529384.

The previous prime is 661721. The next prime is 661741. The reversal of 661735 is 537166.

661735 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 is a cyclic number.

It is not a de Polignac number, because 661735 - 2⁷ = 661607 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 66169 + ... + 66178.

It is an arithmetic number, because the mean of its divisors is an integer number (198522).

2⁶⁶¹⁷³⁵ is an apocalyptic number.

661735 is a deficient number, since it is larger than the sum of its proper divisors (132353).

661735 is a wasteful number, since it uses less digits than its factorization.

661735 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 132352.

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

The square root of 661735 is about 813.4709583015. The cubic root of 661735 is about 87.1421027308.

The spelling of 661735 in words is "six hundred sixty-one thousand, seven hundred thirty-five".