66401428 has 24 divisors (see below), whose sum is σ = 124332320. Its totient is φ = 30935520.

The previous prime is 66401407. The next prime is 66401429. The reversal of 66401428 is 82410466.

It is a self number, because there is not a number n which added to its sum of digits gives 66401428.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66401429) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2526 + ... + 11797.

Almost surely, 2^66401428 is an apocalyptic number.

It is an amenable number.

66401428 is a deficient number, since it is larger than the sum of its proper divisors (57930892).

66401428 is a wasteful number, since it uses less digits than its factorization.

66401428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14407 (or 14405 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 31.

The square root of 66401428 is about 8148.7071367181. The cubic root of 66401428 is about 404.9416732546.

The spelling of 66401428 in words is "sixty-six million, four hundred one thousand, four hundred twenty-eight".