21428109186 has 32 divisors (see below), whose sum is σ = 46770932736. Its totient is φ = 6490770000.

The previous prime is 21428109181. The next prime is 21428109223. The reversal of 21428109186 is 68190182412.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21428109181) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 104731 + ... + 232001.

It is an arithmetic number, because the mean of its divisors is an integer number (1461591648).

Almost surely, 2^21428109186 is an apocalyptic number.

21428109186 is an abundant number, since it is smaller than the sum of its proper divisors (25342823550).

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

21428109186 is a wasteful number, since it uses less digits than its factorization.

21428109186 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 129838.

The product of its (nonzero) digits is 55296, while the sum is 42.

The spelling of 21428109186 in words is "twenty-one billion, four hundred twenty-eight million, one hundred nine thousand, one hundred eighty-six".