66457664 has 56 divisors (see below), whose sum is σ = 162324288. Its totient is φ = 26288640.

The previous prime is 66457639. The next prime is 66457691. The reversal of 66457664 is 46675466.

It is a tau number, because it is divible by the number of its divisors (56).

It is a super-2 number, since 2×66457664² = 8833242208673792, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 119 + ... + 11529.

It is an arithmetic number, because the mean of its divisors is an integer number (2898648).

Almost surely, 2^66457664 is an apocalyptic number.

66457664 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 66457664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (81162144).

66457664 is an abundant number, since it is smaller than the sum of its proper divisors (95866624).

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

66457664 is a wasteful number, since it uses less digits than its factorization.

66457664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11443 (or 11433 counting only the distinct ones).

The product of its digits is 725760, while the sum is 44.

The square root of 66457664 is about 8152.1570151709. The cubic root of 66457664 is about 405.0559573142.

The spelling of 66457664 in words is "sixty-six million, four hundred fifty-seven thousand, six hundred sixty-four".