21586821070 has 16 divisors (see below), whose sum is σ = 39212759520. Its totient is φ = 8555510304.

The previous prime is 21586821049. The next prime is 21586821079. The reversal of 21586821070 is 7012868512.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21586821079) 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, 9901122 + ... + 9903301.

It is an arithmetic number, because the mean of its divisors is an integer number (2450797470).

Almost surely, 2^21586821070 is an apocalyptic number.

21586821070 is a deficient number, since it is larger than the sum of its proper divisors (17625938450).

21586821070 is a wasteful number, since it uses less digits than its factorization.

21586821070 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19804539.

The product of its (nonzero) digits is 53760, while the sum is 40.

The spelling of 21586821070 in words is "twenty-one billion, five hundred eighty-six million, eight hundred twenty-one thousand, seventy".