661368433285 has 24 divisors (see below), whose sum is σ = 923975360280. Its totient is φ = 453136932864.

The previous prime is 661368433241. The next prime is 661368433357. The reversal of 661368433285 is 582334863166.

661368433285 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 142344725796 + 519023707489 = 377286^2 + 720433^2 .

It is not a de Polignac number, because 661368433285 - 2²⁹ = 660831562373 is a prime.

It is a Smith number, since the sum of its digits (55) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 810900 + ... + 1407229.

It is an arithmetic number, because the mean of its divisors is an integer number (38498973345).

Almost surely, 2^661368433285 is an apocalyptic number.

It is an amenable number.

661368433285 is a deficient number, since it is larger than the sum of its proper divisors (262606926995).

661368433285 is a wasteful number, since it uses less digits than its factorization.

661368433285 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2219365 (or 2219358 counting only the distinct ones).

The product of its digits is 14929920, while the sum is 55.

The spelling of 661368433285 in words is "six hundred sixty-one billion, three hundred sixty-eight million, four hundred thirty-three thousand, two hundred eighty-five".