111221211220021 has 32 divisors (see below), whose sum is σ = 138164848803072. Its totient is φ = 87348822282240.

The previous prime is 111221211220013. The next prime is 111221211220027. The reversal of 111221211220021 is 120022112122111.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 111221211220021 - 2³ = 111221211220013 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (111221211220027) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 22128256 + ... + 26685241.

It is an arithmetic number, because the mean of its divisors is an integer number (4317651525096).

Almost surely, 2^{111221211220021} is an apocalyptic number.

It is an amenable number.

111221211220021 is a deficient number, since it is larger than the sum of its proper divisors (26943637583051).

111221211220021 is a wasteful number, since it uses less digits than its factorization.

111221211220021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48814029.

The product of its (nonzero) digits is 64, while the sum is 19.

Adding to 111221211220021 its reverse (120022112122111), we get a palindrome (231243323342132).

The spelling of 111221211220021 in words is "one hundred eleven trillion, two hundred twenty-one billion, two hundred eleven million, two hundred twenty thousand, twenty-one".