111100020021 has 6 divisors (see below), whose sum is σ = 160477806710. Its totient is φ = 74066680008.

The previous prime is 111100019977. The next prime is 111100020023. The reversal of 111100020021 is 120020001111.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 98775689796 + 12324330225 = 314286^2 + 111015^2 .

It is not a de Polignac number, because 111100020021 - 2⁷ = 111100019893 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9), and also a Moran number because the ratio is a prime number: 12344446669 = 111100020021 / (1 + 1 + 1 + 1 + 0 + 0 + 0 + 2 + 0 + 0 + 2 + 1).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 111100019985 and 111100020012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (111100020023) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 6172223326 + ... + 6172223343.

Almost surely, 2^111100020021 is an apocalyptic number.

It is an amenable number.

111100020021 is a deficient number, since it is larger than the sum of its proper divisors (49377786689).

111100020021 is a wasteful number, since it uses less digits than its factorization.

111100020021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12344446675 (or 12344446672 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

Adding to 111100020021 its reverse (120020001111), we get a palindrome (231120021132).

The spelling of 111100020021 in words is "one hundred eleven billion, one hundred million, twenty thousand, twenty-one".