21286440870 has 64 divisors (see below), whose sum is σ = 51321102336. Its totient is φ = 5650484480.

The previous prime is 21286440863. The next prime is 21286440893. The reversal of 21286440870 is 7804468212.

21286440870 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×21286440870² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 7920667 + ... + 7923353.

It is an arithmetic number, because the mean of its divisors is an integer number (801892224).

Almost surely, 2^21286440870 is an apocalyptic number.

21286440870 is an abundant number, since it is smaller than the sum of its proper divisors (30034661466).

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

21286440870 is a wasteful number, since it uses less digits than its factorization.

21286440870 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3805.

The product of its (nonzero) digits is 172032, while the sum is 42.

The spelling of 21286440870 in words is "twenty-one billion, two hundred eighty-six million, four hundred forty thousand, eight hundred seventy".