66611165940 has 192 divisors, whose sum is σ = 227092561920. Its totient is φ = 16075428480.

The previous prime is 66611165921. The next prime is 66611165993. The reversal of 66611165940 is 4956111666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1299477 + ... + 1349763.

It is an arithmetic number, because the mean of its divisors is an integer number (1182773760).

Almost surely, 2^66611165940 is an apocalyptic number.

66611165940 is a gapful number since it is divisible by the number (60) 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 66611165940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (113546280960).

66611165940 is an abundant number, since it is smaller than the sum of its proper divisors (160481395980).

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

66611165940 is a wasteful number, since it uses less digits than its factorization.

66611165940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50539 (or 50531 counting only the distinct ones).

The product of its (nonzero) digits is 233280, while the sum is 45.

The spelling of 66611165940 in words is "sixty-six billion, six hundred eleven million, one hundred sixty-five thousand, nine hundred forty".