21018582012 has 24 divisors (see below), whose sum is σ = 49300134912. Its totient is φ = 6969511600.

The previous prime is 21018581999. The next prime is 21018582037. The reversal of 21018582012 is 21028581012.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4582914 + ... + 4587497.

It is an arithmetic number, because the mean of its divisors is an integer number (2054172288).

Almost surely, 2^21018582012 is an apocalyptic number.

It is an amenable number.

21018582012 is an abundant number, since it is smaller than the sum of its proper divisors (28281552900).

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

21018582012 is a wasteful number, since it uses less digits than its factorization.

21018582012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9170609 (or 9170607 counting only the distinct ones).

The product of its (nonzero) digits is 2560, while the sum is 30.

The spelling of 21018582012 in words is "twenty-one billion, eighteen million, five hundred eighty-two thousand, twelve".