21012112211 has 8 divisors (see below), whose sum is σ = 21159540000. Its totient is φ = 20864793600.

The previous prime is 21012112171. The next prime is 21012112241. The reversal of 21012112211 is 11221121012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21012112211 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21012112241) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 380165 + ... + 431913.

It is an arithmetic number, because the mean of its divisors is an integer number (2644942500).

Almost surely, 2^21012112211 is an apocalyptic number.

21012112211 is a deficient number, since it is larger than the sum of its proper divisors (147427789).

21012112211 is a wasteful number, since it uses less digits than its factorization.

21012112211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54589.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 21012112211 its reverse (11221121012), we get a palindrome (32233233223).

It can be divided in two parts, 21012 and 112211, that multiplied together give a palindrome (2357777532).

The spelling of 21012112211 in words is "twenty-one billion, twelve million, one hundred twelve thousand, two hundred eleven".