661106165104 has 160 divisors (see below), whose sum is σ = 1646681605632. Its totient is φ = 249609600000.

The previous prime is 661106165089. The next prime is 661106165113. The reversal of 661106165104 is 401561601166.

It is a super-2 number, since 2×661106165104² (a number of 24 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (37).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 11412694 + ... + 11470474.

Almost surely, 2^661106165104 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 661106165104, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (823340802816).

661106165104 is an abundant number, since it is smaller than the sum of its proper divisors (985575440528).

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

661106165104 is a wasteful number, since it uses less digits than its factorization.

661106165104 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58095 (or 58089 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 37.

The spelling of 661106165104 in words is "six hundred sixty-one billion, one hundred six million, one hundred sixty-five thousand, one hundred four".