21012220195 has 16 divisors (see below), whose sum is σ = 25410792960. Its totient is φ = 16679434464.

The previous prime is 21012220183. The next prime is 21012220211. The reversal of 21012220195 is 59102221012.

It is a cyclic number.

It is not a de Polignac number, because 21012220195 - 2¹¹ = 21012218147 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 389032 + ... + 439738.

It is an arithmetic number, because the mean of its divisors is an integer number (1588174560).

Almost surely, 2^21012220195 is an apocalyptic number.

21012220195 is a deficient number, since it is larger than the sum of its proper divisors (4398572765).

21012220195 is a wasteful number, since it uses less digits than its factorization.

21012220195 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51354.

The product of its (nonzero) digits is 720, while the sum is 25.

The spelling of 21012220195 in words is "twenty-one billion, twelve million, two hundred twenty thousand, one hundred ninety-five".