20111221043 has 4 divisors (see below), whose sum is σ = 20111504808. Its totient is φ = 20110937280.

The previous prime is 20111221021. The next prime is 20111221057. The reversal of 20111221043 is 34012211102.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 20111221043 - 2¹⁶ = 20111155507 is a prime.

It is a super-2 number, since 2×20111221043² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20111221003) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 64355 + ... + 210627.

It is an arithmetic number, because the mean of its divisors is an integer number (5027876202).

Almost surely, 2^20111221043 is an apocalyptic number.

20111221043 is a deficient number, since it is larger than the sum of its proper divisors (283765).

20111221043 is a wasteful number, since it uses less digits than its factorization.

20111221043 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 283764.

The product of its (nonzero) digits is 96, while the sum is 17.

Adding to 20111221043 its reverse (34012211102), we get a palindrome (54123432145).

The spelling of 20111221043 in words is "twenty billion, one hundred eleven million, two hundred twenty-one thousand, forty-three".