21021000012111 has 16 divisors (see below), whose sum is σ = 30626875254528. Its totient is φ = 12718801992000.

The previous prime is 21021000012059. The next prime is 21021000012113. The reversal of 21021000012111 is 11121000012012.

It is not a de Polignac number, because 21021000012111 - 2²² = 21020995817807 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21021000012113) 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 15 ways as a sum of consecutive naturals, for example, 529930251 + ... + 529969916.

It is an arithmetic number, because the mean of its divisors is an integer number (1914179703408).

Almost surely, 2^{21021000012111} is an apocalyptic number.

21021000012111 is a deficient number, since it is larger than the sum of its proper divisors (9605875242417).

21021000012111 is a wasteful number, since it uses less digits than its factorization.

21021000012111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1059900782.

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 21021000012111 its reverse (11121000012012), we get a palindrome (32142000024123).

Subtracting from 21021000012111 its reverse (11121000012012), we obtain a palindrome (9900000000099).

The spelling of 21021000012111 in words is "twenty-one trillion, twenty-one billion, twelve thousand, one hundred eleven".