66435820 has 48 divisors (see below), whose sum is σ = 152845056. Its totient is φ = 24056000.

The previous prime is 66435797. The next prime is 66435823. The reversal of 66435820 is 2853466.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (66435823) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 67935 + ... + 68905.

It is an arithmetic number, because the mean of its divisors is an integer number (3184272).

Almost surely, 2^66435820 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 66435820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (76422528).

66435820 is an abundant number, since it is smaller than the sum of its proper divisors (86409236).

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

66435820 is a wasteful number, since it uses less digits than its factorization.

66435820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1302 (or 1300 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 34.

The square root of 66435820 is about 8150.8171369501. The cubic root of 66435820 is about 405.0115731083.

The spelling of 66435820 in words is "sixty-six million, four hundred thirty-five thousand, eight hundred twenty".