661740631101 has 120 divisors (see below), whose sum is σ = 1163708071680. Its totient is φ = 371234793600.

The previous prime is 661740631049. The next prime is 661740631117. The reversal of 661740631101 is 101136047166.

661740631101 is a `hidden beast` number, since 6 + 6 + 1 + 7 + 4 + 0 + 631 + 10 + 1 = 666.

It is not a de Polignac number, because 661740631101 - 2⁹ = 661740630589 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661740631121) by changing a digit.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 14588865 + ... + 14634153.

It is an arithmetic number, because the mean of its divisors is an integer number (9697567264).

Almost surely, 2^661740631101 is an apocalyptic number.

It is an amenable number.

661740631101 is a deficient number, since it is larger than the sum of its proper divisors (501967440579).

661740631101 is a wasteful number, since it uses less digits than its factorization.

661740631101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45389 (or 45357 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 36.

Adding to 661740631101 its reverse (101136047166), we get a palindrome (762876678267).

The spelling of 661740631101 in words is "six hundred sixty-one billion, seven hundred forty million, six hundred thirty-one thousand, one hundred one".