66257664 has 216 divisors, whose sum is σ = 208782336. Its totient is φ = 18585600.

The previous prime is 66257657. The next prime is 66257677. The reversal of 66257664 is 46675266.

Its product of digits (362880) is a multiple of the sum of its prime divisors (70).

It is a zygodrome in base 2.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2137329 + ... + 2137359.

Almost surely, 2^66257664 is an apocalyptic number.

66257664 is a gapful number since it is divisible by the number (64) 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 66257664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (104391168).

66257664 is an abundant number, since it is smaller than the sum of its proper divisors (142524672).

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

66257664 is a wasteful number, since it uses less digits than its factorization.

66257664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95 (or 70 counting only the distinct ones).

The product of its digits is 362880, while the sum is 42.

The square root of 66257664 is about 8139.8810802124. The cubic root of 66257664 is about 404.6492192061.

The spelling of 66257664 in words is "sixty-six million, two hundred fifty-seven thousand, six hundred sixty-four".