66400032 has 48 divisors (see below), whose sum is σ = 175234752. Its totient is φ = 22014720.

The previous prime is 66400021. The next prime is 66400051. The reversal of 66400032 is 23000466.

It is a tau number, because it is divible by the number of its divisors (48).

It is a junction number, because it is equal to n+sod(n) for n = 66399981 and 66400008.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17157 + ... + 20667.

It is an arithmetic number, because the mean of its divisors is an integer number (3650724).

Almost surely, 2^66400032 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 66400032, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (87617376).

66400032 is an abundant number, since it is smaller than the sum of its proper divisors (108834720).

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

66400032 is a wasteful number, since it uses less digits than its factorization.

66400032 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3721 (or 3713 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 21.

The square root of 66400032 is about 8148.6214785079. The cubic root of 66400032 is about 404.9388354515.

Adding to 66400032 its reverse (23000466), we get a palindrome (89400498).

The spelling of 66400032 in words is "sixty-six million, four hundred thousand, thirty-two".