21012201111 has 16 divisors (see below), whose sum is σ = 31617106560. Its totient is φ = 12295540320.

The previous prime is 21012201107. The next prime is 21012201113. The reversal of 21012201111 is 11110221012.

It is not a de Polignac number, because 21012201111 - 2² = 21012201107 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21012201113) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10977205 + ... + 10979118.

It is an arithmetic number, because the mean of its divisors is an integer number (1976069160).

Almost surely, 2^21012201111 is an apocalyptic number.

21012201111 is a deficient number, since it is larger than the sum of its proper divisors (10604905449).

21012201111 is a wasteful number, since it uses less digits than its factorization.

21012201111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21956366.

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

Adding to 21012201111 its reverse (11110221012), we get a palindrome (32122422123).

The spelling of 21012201111 in words is "twenty-one billion, twelve million, two hundred one thousand, one hundred eleven".