21020011999 has 32 divisors (see below), whose sum is σ = 25528320000. Its totient is φ = 16906960224.

The previous prime is 21020011973. The next prime is 21020012059. The reversal of 21020011999 is 99911002012.

It is not a de Polignac number, because 21020011999 - 2¹¹ = 21020009951 is a prime.

It is a super-3 number, since 3×21020011999³ (a number of 32 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21020011919) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6323952 + ... + 6327274.

It is an arithmetic number, because the mean of its divisors is an integer number (797760000).

Almost surely, 2^21020011999 is an apocalyptic number.

21020011999 is a deficient number, since it is larger than the sum of its proper divisors (4508308001).

21020011999 is a wasteful number, since it uses less digits than its factorization.

21020011999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3787.

The product of its (nonzero) digits is 2916, while the sum is 34.

The spelling of 21020011999 in words is "twenty-one billion, twenty million, eleven thousand, nine hundred ninety-nine".