66501888 has 72 divisors (see below), whose sum is σ = 178612896. Its totient is φ = 21964800.

The previous prime is 66501863. The next prime is 66501889. The reversal of 66501888 is 88810566.

It is a super-2 number, since 2×66501888² = 8845002215129088, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66501889) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 100278 + ... + 100938.

Almost surely, 2^66501888 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 66501888, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (89306448).

66501888 is an abundant number, since it is smaller than the sum of its proper divisors (112111008).

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

66501888 is a wasteful number, since it uses less digits than its factorization.

66501888 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 811 (or 797 counting only the distinct ones).

The product of its (nonzero) digits is 92160, while the sum is 42.

The square root of 66501888 is about 8154.8689750357. The cubic root of 66501888 is about 405.1457850412.

The spelling of 66501888 in words is "sixty-six million, five hundred one thousand, eight hundred eighty-eight".