111020100021 has 12 divisors (see below), whose sum is σ = 168802491520. Its totient is φ = 70117957800.

The previous prime is 111020099947. The next prime is 111020100031. The reversal of 111020100021 is 120001020111.

It is a happy number.

It is not a de Polignac number, because 111020100021 - 2³⁴ = 93840230837 is a prime.

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

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 111020099976 and 111020100012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (111020100031) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 324620005 + ... + 324620346.

Almost surely, 2^111020100021 is an apocalyptic number.

It is an amenable number.

111020100021 is a deficient number, since it is larger than the sum of its proper divisors (57782391499).

111020100021 is a wasteful number, since it uses less digits than its factorization.

111020100021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 649240376 (or 649240373 counting only the distinct ones).

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

Adding to 111020100021 its reverse (120001020111), we get a palindrome (231021120132).

The spelling of 111020100021 in words is "one hundred eleven billion, twenty million, one hundred thousand, twenty-one".