21001011211999 has 12 divisors (see below), whose sum is σ = 26308959101544. Its totient is φ = 16616184694704.

The previous prime is 21001011211967. The next prime is 21001011212021. The reversal of 21001011211999 is 99911211010012.

It is not a de Polignac number, because 21001011211999 - 2⁵ = 21001011211967 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21001011211909) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 16484309577 + ... + 16484310850.

It is an arithmetic number, because the mean of its divisors is an integer number (2192413258462).

Almost surely, 2^{21001011211999} is an apocalyptic number.

21001011211999 is a deficient number, since it is larger than the sum of its proper divisors (5307947889545).

21001011211999 is a wasteful number, since it uses less digits than its factorization.

21001011211999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32968620454 (or 32968620447 counting only the distinct ones).

The product of its (nonzero) digits is 2916, while the sum is 37.

The spelling of 21001011211999 in words is "twenty-one trillion, one billion, eleven million, two hundred eleven thousand, nine hundred ninety-nine".