66380400 has 90 divisors (see below), whose sum is σ = 230370920. Its totient is φ = 17700480.

The previous prime is 66380399. The next prime is 66380401. The reversal of 66380400 is 408366.

It is an interprime number because it is at equal distance from previous prime (66380399) and next prime (66380401).

It is a tau number, because it is divible by the number of its divisors (90).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66380401) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 5620 + ... + 12819.

Almost surely, 2^66380400 is an apocalyptic number.

66380400 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

66380400 is an abundant number, since it is smaller than the sum of its proper divisors (163990520).

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

66380400 is a wasteful number, since it uses less digits than its factorization.

66380400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18463 (or 18449 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 27.

The square root of 66380400 is about 8147.4167685224. The cubic root of 66380400 is about 404.8989231071.

Adding to 66380400 its reverse (408366), we get a palindrome (66788766).

The spelling of 66380400 in words is "sixty-six million, three hundred eighty thousand, four hundred".