21113111020212 has 18 divisors (see below), whose sum is σ = 53369252856738. Its totient is φ = 7037703673392.

The previous prime is 21113111020187. The next prime is 21113111020297. The reversal of 21113111020212 is 21202011131112.

It is a happy number.

21113111020212 is a `hidden beast` number, since 2 + 111 + 311 + 10 + 20 + 212 = 666.

It can be written as a sum of positive squares in only one way, i.e., 12777221826576 + 8335889193636 = 3574524^2 + 2887194^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 293237653023 + ... + 293237653094.

It is an arithmetic number, because the mean of its divisors is an integer number (2964958492041).

Almost surely, 2^{21113111020212} is an apocalyptic number.

It is an amenable number.

21113111020212 is an abundant number, since it is smaller than the sum of its proper divisors (32256141836526).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21113111020212 is a wasteful number, since it uses less digits than its factorization.

21113111020212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 586475306127 (or 586475306122 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 18.

Adding to 21113111020212 its reverse (21202011131112), we get a palindrome (42315122151324).

The spelling of 21113111020212 in words is "twenty-one trillion, one hundred thirteen billion, one hundred eleven million, twenty thousand, two hundred twelve".