21043029992 has 8 divisors (see below), whose sum is σ = 39455681250. Its totient is φ = 10521514992.

The previous prime is 21043029991. The next prime is 21043030003. The reversal of 21043029992 is 29992034012.

It can be written as a sum of positive squares in only one way, i.e., 20818449796 + 224580196 = 144286^2 + 14986^2 .

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

It is a super-2 number, since 2×21043029992² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21043029991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1315189367 + ... + 1315189382.

Almost surely, 2^21043029992 is an apocalyptic number.

It is an amenable number.

21043029992 is a deficient number, since it is larger than the sum of its proper divisors (18412651258).

21043029992 is a wasteful number, since it uses less digits than its factorization.

21043029992 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2630378755 (or 2630378751 counting only the distinct ones).

The product of its (nonzero) digits is 69984, while the sum is 41.

The spelling of 21043029992 in words is "twenty-one billion, forty-three million, twenty-nine thousand, nine hundred ninety-two".