661100010516 has 144 divisors (see below), whose sum is σ = 1856476177920. Its totient is φ = 196667634240.

The previous prime is 661100010511. The next prime is 661100010517. The reversal of 661100010516 is 615010001166.

It is a self number, because there is not a number n which added to its sum of digits gives 661100010516.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661100010511) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 17340411 + ... + 17378493.

It is an arithmetic number, because the mean of its divisors is an integer number (12892195680).

Almost surely, 2^661100010516 is an apocalyptic number.

661100010516 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 661100010516, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (928238088960).

661100010516 is an abundant number, since it is smaller than the sum of its proper divisors (1195376167404).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

661100010516 is a wasteful number, since it uses less digits than its factorization.

661100010516 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38906 (or 38901 counting only the distinct ones).

The product of its (nonzero) digits is 1080, while the sum is 27.

The spelling of 661100010516 in words is "six hundred sixty-one billion, one hundred million, ten thousand, five hundred sixteen".