66145131864 has 192 divisors, whose sum is σ = 215269704000. Its totient is φ = 17947560960.

The previous prime is 66145131841. The next prime is 66145131947. The reversal of 66145131864 is 46813154166.

66145131864 is a `hidden beast` number, since 6 + 61 + 4 + 513 + 18 + 64 = 666.

It is a super-2 number, since 2×66145131864² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 854482 + ... + 928670.

It is an arithmetic number, because the mean of its divisors is an integer number (1121196375).

Almost surely, 2^66145131864 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 66145131864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (107634852000).

66145131864 is an abundant number, since it is smaller than the sum of its proper divisors (149124572136).

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

66145131864 is a wasteful number, since it uses less digits than its factorization.

66145131864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74298 (or 74291 counting only the distinct ones).

The product of its digits is 414720, while the sum is 45.

The spelling of 66145131864 in words is "sixty-six billion, one hundred forty-five million, one hundred thirty-one thousand, eight hundred sixty-four".