66439520 has 96 divisors (see below), whose sum is σ = 181113408. Its totient is φ = 22560768.

The previous prime is 66439511. The next prime is 66439537. The reversal of 66439520 is 2593466.

It is a hoax number, since the sum of its digits (35) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (35).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 153224 + ... + 153656.

It is an arithmetic number, because the mean of its divisors is an integer number (1886598).

Almost surely, 2^66439520 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 66439520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (90556704).

66439520 is an abundant number, since it is smaller than the sum of its proper divisors (114673888).

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

66439520 is a wasteful number, since it uses less digits than its factorization.

66439520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 592 (or 584 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 35.

The square root of 66439520 is about 8151.0441048985. The cubic root of 66439520 is about 405.0190917180.

The spelling of 66439520 in words is "sixty-six million, four hundred thirty-nine thousand, five hundred twenty".