21531066870 has 16 divisors (see below), whose sum is σ = 51674560560. Its totient is φ = 5741617824.

The previous prime is 21531066857. The next prime is 21531066871. The reversal of 21531066870 is 7866013512.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21531066871) 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, 358851085 + ... + 358851144.

It is an arithmetic number, because the mean of its divisors is an integer number (3229660035).

Almost surely, 2^21531066870 is an apocalyptic number.

21531066870 is an abundant number, since it is smaller than the sum of its proper divisors (30143493690).

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

21531066870 is a wasteful number, since it uses less digits than its factorization.

21531066870 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 717702239.

The product of its (nonzero) digits is 60480, while the sum is 39.

The spelling of 21531066870 in words is "twenty-one billion, five hundred thirty-one million, sixty-six thousand, eight hundred seventy".