66415800 has 192 divisors, whose sum is σ = 233020800. Its totient is φ = 15500800.

The previous prime is 66415799. The next prime is 66415813. The reversal of 66415800 is 851466.

It is a super-2 number, since 2×66415800² = 8822116979280000, which contains 22 as substring.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 191227 + ... + 191573.

It is an arithmetic number, because the mean of its divisors is an integer number (1213650).

Almost surely, 2^66415800 is an apocalyptic number.

66415800 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66415800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (116510400).

66415800 is an abundant number, since it is smaller than the sum of its proper divisors (166605000).

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

66415800 is a wasteful number, since it uses less digits than its factorization.

66415800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 406 (or 397 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 30.

The square root of 66415800 is about 8149.5889466893. The cubic root of 66415800 is about 404.9708864913.

The spelling of 66415800 in words is "sixty-six million, four hundred fifteen thousand, eight hundred".