66220770 has 128 divisors (see below), whose sum is σ = 200724480. Its totient is φ = 13582080.

The previous prime is 66220769. The next prime is 66220771. The reversal of 66220770 is 7702266.

It is an interprime number because it is at equal distance from previous prime (66220769) and next prime (66220771).

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 (66220771) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 251659 + ... + 251921.

It is an arithmetic number, because the mean of its divisors is an integer number (1568160).

Almost surely, 2^66220770 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66220770, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (100362240).

66220770 is an abundant number, since it is smaller than the sum of its proper divisors (134503710).

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

66220770 is a wasteful number, since it uses less digits than its factorization.

66220770 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 400.

The product of its (nonzero) digits is 7056, while the sum is 30.

The square root of 66220770 is about 8137.6145153233. The cubic root of 66220770 is about 404.5740988390.

The spelling of 66220770 in words is "sixty-six million, two hundred twenty thousand, seven hundred seventy".