111002100021 has 24 divisors (see below), whose sum is σ = 160843292064. Its totient is φ = 73767762720.

The previous prime is 111002099969. The next prime is 111002100043. The reversal of 111002100021 is 120001200111.

It is a happy number.

It is not a de Polignac number, because 111002100021 - 2¹⁰ = 111002098997 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a junction number, because it is equal to n+sod(n) for n = 111002099976 and 111002100012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (111002100061) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4278330 + ... + 4304196.

It is an arithmetic number, because the mean of its divisors is an integer number (6701803836).

Almost surely, 2^111002100021 is an apocalyptic number.

It is an amenable number.

111002100021 is a deficient number, since it is larger than the sum of its proper divisors (49841192043).

111002100021 is a wasteful number, since it uses less digits than its factorization.

111002100021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27361 (or 27358 counting only the distinct ones).

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

Adding to 111002100021 its reverse (120001200111), we get a palindrome (231003300132).

The spelling of 111002100021 in words is "one hundred eleven billion, two million, one hundred thousand, twenty-one".