21210021092 has 12 divisors (see below), whose sum is σ = 39972732156. Its totient is φ = 9789240480.

The previous prime is 21210021071. The next prime is 21210021103. The reversal of 21210021092 is 29012001212.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 6507003556 + 14703017536 = 80666^2 + 121256^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 203942459 + ... + 203942562.

It is an arithmetic number, because the mean of its divisors is an integer number (3331061013).

Almost surely, 2^21210021092 is an apocalyptic number.

It is an amenable number.

21210021092 is a deficient number, since it is larger than the sum of its proper divisors (18762711064).

21210021092 is a wasteful number, since it uses less digits than its factorization.

21210021092 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 407885038 (or 407885036 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 20.

The spelling of 21210021092 in words is "twenty-one billion, two hundred ten million, twenty-one thousand, ninety-two".