66101840 has 80 divisors (see below), whose sum is σ = 179988480. Its totient is φ = 22103040.

The previous prime is 66101837. The next prime is 66101873. The reversal of 66101840 is 4810166.

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 21521 + ... + 24399.

It is an arithmetic number, because the mean of its divisors is an integer number (2249856).

Almost surely, 2^66101840 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 66101840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (89994240).

66101840 is an abundant number, since it is smaller than the sum of its proper divisors (113886640).

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

66101840 is a wasteful number, since it uses less digits than its factorization.

66101840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2940 (or 2934 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 26.

The square root of 66101840 is about 8130.3038073617. The cubic root of 66101840 is about 404.3317537702.

The spelling of 66101840 in words is "sixty-six million, one hundred one thousand, eight hundred forty".