66940400 has 60 divisors (see below), whose sum is σ = 165207432. Its totient is φ = 26046720.

The previous prime is 66940387. The next prime is 66940411. The reversal of 66940400 is 404966.

66940400 is nontrivially palindromic in base 15.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 12539 + ... + 17061.

Almost surely, 2^66940400 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 66940400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (82603716).

66940400 is an abundant number, since it is smaller than the sum of its proper divisors (98267032).

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

66940400 is a wasteful number, since it uses less digits than its factorization.

66940400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4578 (or 4567 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 29.

The square root of 66940400 is about 8181.7113124334. The cubic root of 66940400 is about 406.0343423432.

The spelling of 66940400 in words is "sixty-six million, nine hundred forty thousand, four hundred".