661698735 has 24 divisors (see below), whose sum is σ = 1124666256. Its totient is φ = 332144640.

The previous prime is 661698727. The next prime is 661698823. The reversal of 661698735 is 537896166.

It is not a de Polignac number, because 661698735 - 2³ = 661698727 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 71986 + ... + 80655.

It is an arithmetic number, because the mean of its divisors is an integer number (46861094).

Almost surely, 2^661698735 is an apocalyptic number.

661698735 is a deficient number, since it is larger than the sum of its proper divisors (462967521).

661698735 is a wasteful number, since it uses less digits than its factorization.

661698735 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 152683 (or 152666 counting only the distinct ones).

The product of its digits is 1632960, while the sum is 51.

The square root of 661698735 is about 25723.5054959467. The cubic root of 661698735 is about 871.4051082164.

The spelling of 661698735 in words is "six hundred sixty-one million, six hundred ninety-eight thousand, seven hundred thirty-five".