66210768 has 120 divisors (see below), whose sum is σ = 201961032. Its totient is φ = 20127744.

The previous prime is 66210757. The next prime is 66210779. The reversal of 66210768 is 86701266.

It is a happy number.

It is a Cunningham number, because it is equal to 8137²-1.

It is an interprime number because it is at equal distance from previous prime (66210757) and next prime (66210779).

It can be written as a sum of positive squares in 4 ways, for example, as 14197824 + 52012944 = 3768^2 + 7212^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 211380 + ... + 211692.

Almost surely, 2^66210768 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 66210768, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (100980516).

66210768 is an abundant number, since it is smaller than the sum of its proper divisors (135750264).

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

66210768 is a wasteful number, since it uses less digits than its factorization.

66210768 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 453 (or 444 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 36.

The square root of 66210768 is about 8136.9999385523. Note that the first 4 decimals coincide. The cubic root of 66210768 is about 404.5537288258.

The spelling of 66210768 in words is "sixty-six million, two hundred ten thousand, seven hundred sixty-eight".