66210690 has 128 divisors (see below), whose sum is σ = 198696960. Its totient is φ = 13747968.

The previous prime is 66210689. The next prime is 66210691. The reversal of 66210690 is 9601266.

66210690 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (66210689) and next prime (66210691).

It is a super-2 number, since 2×66210690² = 8767710940552200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is not an unprimeable number, because it can be changed into a prime (66210691) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 215517 + ... + 215823.

It is an arithmetic number, because the mean of its divisors is an integer number (1552320).

Almost surely, 2^66210690 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66210690, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (99348480).

66210690 is an abundant number, since it is smaller than the sum of its proper divisors (132486270).

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

66210690 is a wasteful number, since it uses less digits than its factorization.

66210690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 416.

The product of its (nonzero) digits is 3888, while the sum is 30.

The square root of 66210690 is about 8136.9951456296. The cubic root of 66210690 is about 404.5535699634.

The spelling of 66210690 in words is "sixty-six million, two hundred ten thousand, six hundred ninety".