21206510060 has 24 divisors (see below), whose sum is σ = 44678744880. Its totient is φ = 8454970944.

The previous prime is 21206510051. The next prime is 21206510063. The reversal of 21206510060 is 6001560212.

It is not an unprimeable number, because it can be changed into a prime (21206510063) 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, 1720775 + ... + 1733054.

It is an arithmetic number, because the mean of its divisors is an integer number (1861614370).

Almost surely, 2^21206510060 is an apocalyptic number.

21206510060 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21206510060 is an abundant number, since it is smaller than the sum of its proper divisors (23472234820).

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

21206510060 is a wasteful number, since it uses less digits than its factorization.

21206510060 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3454145 (or 3454143 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 23.

The spelling of 21206510060 in words is "twenty-one billion, two hundred six million, five hundred ten thousand, sixty".