21286883891 has 32 divisors (see below), whose sum is σ = 27282662400. Its totient is φ = 16153603200.

The previous prime is 21286883887. The next prime is 21286883899. The reversal of 21286883891 is 19838868212.

It is a happy number.

It is not a de Polignac number, because 21286883891 - 2² = 21286883887 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21286883899) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 371780 + ... + 425198.

It is an arithmetic number, because the mean of its divisors is an integer number (852583200).

Almost surely, 2^21286883891 is an apocalyptic number.

21286883891 is a deficient number, since it is larger than the sum of its proper divisors (5995778509).

21286883891 is a wasteful number, since it uses less digits than its factorization.

21286883891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53619.

The product of its digits is 2654208, while the sum is 56.

The spelling of 21286883891 in words is "twenty-one billion, two hundred eighty-six million, eight hundred eighty-three thousand, eight hundred ninety-one".