66211560 has 128 divisors (see below), whose sum is σ = 223257600. Its totient is φ = 17452800.

The previous prime is 66211499. The next prime is 66211591. The reversal of 66211560 is 6511266.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 108777 + ... + 109383.

It is an arithmetic number, because the mean of its divisors is an integer number (1744200).

Almost surely, 2^66211560 is an apocalyptic number.

66211560 is a gapful number since it is divisible by the number (60) 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 66211560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (111628800).

66211560 is an abundant number, since it is smaller than the sum of its proper divisors (157046040).

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

66211560 is a wasteful number, since it uses less digits than its factorization.

66211560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 728 (or 718 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 27.

The square root of 66211560 is about 8137.0486049919. The cubic root of 66211560 is about 404.5553418830. Note that the first 3 decimals are identical.

The spelling of 66211560 in words is "sixty-six million, two hundred eleven thousand, five hundred sixty".