661885293 has 16 divisors (see below), whose sum is σ = 935176320. Its totient is φ = 414967296.

The previous prime is 661885291. The next prime is 661885297. The reversal of 661885293 is 392588166.

It is a happy number.

It is not a de Polignac number, because 661885293 - 2¹ = 661885291 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661885291) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 69313 + ... + 78281.

It is an arithmetic number, because the mean of its divisors is an integer number (58448520).

Almost surely, 2^661885293 is an apocalyptic number.

It is an amenable number.

661885293 is a deficient number, since it is larger than the sum of its proper divisors (273291027).

661885293 is a wasteful number, since it uses less digits than its factorization.

661885293 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10436.

The product of its digits is 622080, while the sum is 48.

The square root of 661885293 is about 25727.1314568881. The cubic root of 661885293 is about 871.4869945845.

The spelling of 661885293 in words is "six hundred sixty-one million, eight hundred eighty-five thousand, two hundred ninety-three".