21111212011001 has 48 divisors (see below), whose sum is σ = 25689478510080. Its totient is φ = 17265502235520.

The previous prime is 21111212010979. The next prime is 21111212011049. The reversal of 21111212011001 is 10011021211112.

It is not a de Polignac number, because 21111212011001 - 2¹⁸ = 21111211748857 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21111212011051) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2720863760 + ... + 2720871518.

It is an arithmetic number, because the mean of its divisors is an integer number (535197468960).

Almost surely, 2^{21111212011001} is an apocalyptic number.

It is an amenable number.

21111212011001 is a deficient number, since it is larger than the sum of its proper divisors (4578266499079).

21111212011001 is a wasteful number, since it uses less digits than its factorization.

21111212011001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13494 (or 13487 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 14.

Adding to 21111212011001 its reverse (10011021211112), we get a palindrome (31122233222113).

The spelling of 21111212011001 in words is "twenty-one trillion, one hundred eleven billion, two hundred twelve million, eleven thousand, one".