21202101992 has 8 divisors (see below), whose sum is σ = 39753941250. Its totient is φ = 10601050992.

The previous prime is 21202101959. The next prime is 21202101997. The reversal of 21202101992 is 29910120212.

It can be written as a sum of positive squares in only one way, i.e., 20401551556 + 800550436 = 142834^2 + 28294^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is not an unprimeable number, because it can be changed into a prime (21202101997) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1325131367 + ... + 1325131382.

Almost surely, 2^21202101992 is an apocalyptic number.

It is an amenable number.

21202101992 is a deficient number, since it is larger than the sum of its proper divisors (18551839258).

21202101992 is a wasteful number, since it uses less digits than its factorization.

21202101992 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2650262755 (or 2650262751 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 29.

The spelling of 21202101992 in words is "twenty-one billion, two hundred two million, one hundred one thousand, nine hundred ninety-two".