21000121192 has 32 divisors (see below), whose sum is σ = 39782356200. Its totient is φ = 10391584000.

The previous prime is 21000121187. The next prime is 21000121211. The reversal of 21000121192 is 29112100012.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 18855134596 + 2144986596 = 137314^2 + 46314^2 .

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, 2598534 + ... + 2606602.

Almost surely, 2^21000121192 is an apocalyptic number.

It is an amenable number.

21000121192 is a deficient number, since it is larger than the sum of its proper divisors (18782235008).

21000121192 is a wasteful number, since it uses less digits than its factorization.

21000121192 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11397 (or 11393 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 19.

The spelling of 21000121192 in words is "twenty-one billion, one hundred twenty-one thousand, one hundred ninety-two".