21100211992 has 8 divisors (see below), whose sum is σ = 39562897500. Its totient is φ = 10550105992.

The previous prime is 21100211933. The next prime is 21100212059. The reversal of 21100211992 is 29911200112.

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

It is a super-2 number, since 2×21100211992² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21100211992.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1318763242 + ... + 1318763257.

Almost surely, 2^21100211992 is an apocalyptic number.

It is an amenable number.

21100211992 is a deficient number, since it is larger than the sum of its proper divisors (18462685508).

21100211992 is a wasteful number, since it uses less digits than its factorization.

21100211992 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2637526505 (or 2637526501 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 28.

The spelling of 21100211992 in words is "twenty-one billion, one hundred million, two hundred eleven thousand, nine hundred ninety-two".