66400228404 has 36 divisors (see below), whose sum is σ = 169506862980. Its totient is φ = 21914265600.

The previous prime is 66400228361. The next prime is 66400228441. The reversal of 66400228404 is 40482200466.

It is a happy number.

66400228404 is a `hidden beast` number, since 6 + 640 + 0 + 2 + 2 + 8 + 4 + 0 + 4 = 666.

66400228404 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 27457152804 + 38943075600 = 165702^2 + 197340^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

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, 9127309 + ... + 9134580.

Almost surely, 2^66400228404 is an apocalyptic number.

It is an amenable number.

66400228404 is an abundant number, since it is smaller than the sum of its proper divisors (103106634576).

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

66400228404 is a wasteful number, since it uses less digits than its factorization.

66400228404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18262000 (or 18261995 counting only the distinct ones).

The product of its (nonzero) digits is 73728, while the sum is 36.

The spelling of 66400228404 in words is "sixty-six billion, four hundred million, two hundred twenty-eight thousand, four hundred four".