661342645053 has 14 divisors (see below), whose sum is σ = 991560372894. Its totient is φ = 440895096216.

The previous prime is 661342645021. The next prime is 661342645099. The reversal of 661342645053 is 350546243166.

661342645053 is a `hidden beast` number, since 6 + 6 + 134 + 2 + 6 + 4 + 505 + 3 = 666.

It can be written as a sum of positive squares in only one way, i.e., 346736078649 + 314606566404 = 588843^2 + 560898^2 .

It is not a de Polignac number, because 661342645053 - 2⁵ = 661342645021 is a prime.

It is a super-3 number, since 3×661342645053³ (a number of 36 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661342645013) by changing a digit.

It is a polite number, since it can be written in 13 ways as a sum of consecutive naturals, for example, 453595050 + ... + 453596507.

It is an arithmetic number, because the mean of its divisors is an integer number (70825740921).

Almost surely, 2^661342645053 is an apocalyptic number.

It is an amenable number.

661342645053 is a deficient number, since it is larger than the sum of its proper divisors (330217727841).

661342645053 is an frugal number, since it uses more digits than its factorization.

661342645053 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 907191575 (or 907191560 counting only the distinct ones).

The product of its (nonzero) digits is 1555200, while the sum is 45.

The spelling of 661342645053 in words is "six hundred sixty-one billion, three hundred forty-two million, six hundred forty-five thousand, fifty-three".