21012042999 has 8 divisors (see below), whose sum is σ = 28019203840. Its totient is φ = 14006455416.

The previous prime is 21012042991. The next prime is 21012043021. The reversal of 21012042999 is 99924021012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21012042999 - 2³ = 21012042991 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21012042991) by changing a digit.

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 in 7 ways as a sum of consecutive naturals, for example, 361789 + ... + 415830.

It is an arithmetic number, because the mean of its divisors is an integer number (3502400480).

Almost surely, 2^21012042999 is an apocalyptic number.

21012042999 is a deficient number, since it is larger than the sum of its proper divisors (7007160841).

21012042999 is an equidigital number, since it uses as much as digits as its factorization.

21012042999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 786629.

The product of its (nonzero) digits is 23328, while the sum is 39.

The spelling of 21012042999 in words is "twenty-one billion, twelve million, forty-two thousand, nine hundred ninety-nine".