66563500 has 96 divisors (see below), whose sum is σ = 158505984. Its totient is φ = 24320000.

The previous prime is 66563491. The next prime is 66563503. The reversal of 66563500 is 536566.

It is a happy number.

It is a hoax number, since the sum of its digits (31) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (66563503) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 348405 + ... + 348595.

It is an arithmetic number, because the mean of its divisors is an integer number (1651104).

Almost surely, 2^66563500 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 66563500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (79252992).

66563500 is an abundant number, since it is smaller than the sum of its proper divisors (91942484).

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

66563500 is a wasteful number, since it uses less digits than its factorization.

66563500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 268 (or 256 counting only the distinct ones).

The product of its (nonzero) digits is 16200, while the sum is 31.

The square root of 66563500 is about 8158.6457209515. The cubic root of 66563500 is about 405.2708648850.

It can be divided in two parts, 66 and 563500, that multiplied together give a triangular number (37191000 = T₈₆₂₄).

The spelling of 66563500 in words is "sixty-six million, five hundred sixty-three thousand, five hundred".