866128401 has 12 divisors (see below), whose sum is σ = 1251341520. Its totient is φ = 577295640.

The previous prime is 866128397. The next prime is 866128409. The reversal of 866128401 is 104821668.

It is not a de Polignac number, because 866128401 - 2² = 866128397 is a prime.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (866128409) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 58306 + ... + 71636.

It is an arithmetic number, because the mean of its divisors is an integer number (104278460).

Almost surely, 2^866128401 is an apocalyptic number.

It is an amenable number.

866128401 is a deficient number, since it is larger than the sum of its proper divisors (385213119).

866128401 is a wasteful number, since it uses less digits than its factorization.

866128401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20556 (or 20553 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 36.

The square root of 866128401 is about 29430.0594800622. The cubic root of 866128401 is about 953.2220792004. Note that the first 3 decimals are identical.

It can be divided in two parts, 86 and 6128401, that added together give a cube (6128487 = 183³).

The spelling of 866128401 in words is "eight hundred sixty-six million, one hundred twenty-eight thousand, four hundred one".