1021020111 has 6 divisors (see below), whose sum is σ = 1474806840. Its totient is φ = 680680068.

The previous prime is 1021020109. The next prime is 1021020149. The reversal of 1021020111 is 1110201201.

It is a happy number.

It is not a de Polignac number, because 1021020111 - 2¹ = 1021020109 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: 113446679 = 1021020111 / (1 + 0 + 2 + 1 + 0 + 2 + 0 + 1 + 1 + 1).

It is a junction number, because it is equal to n+sod(n) for n = 1021020093 and 1021020102.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1021020181) 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, 56723331 + ... + 56723348.

It is an arithmetic number, because the mean of its divisors is an integer number (245801140).

Almost surely, 2^1021020111 is an apocalyptic number.

1021020111 is a deficient number, since it is larger than the sum of its proper divisors (453786729).

1021020111 is a wasteful number, since it uses less digits than its factorization.

1021020111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 113446685 (or 113446682 counting only the distinct ones).

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

The square root of 1021020111 is about 31953.4053114844. The cubic root of 1021020111 is about 1006.9581751688.

Adding to 1021020111 its reverse (1110201201), we get a palindrome (2131221312).

The spelling of 1021020111 in words is "one billion, twenty-one million, twenty thousand, one hundred eleven".