1020111221 has 4 divisors (see below), whose sum is σ = 1055287500. Its totient is φ = 984934944.

The previous prime is 1020111187. The next prime is 1020111263. The reversal of 1020111221 is 1221110201.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1221110201 = 73 ⋅16727537.

It can be written as a sum of positive squares in 2 ways, for example, as 624300196 + 395811025 = 24986^2 + 19895^2 .

It is a cyclic number.

It is not a de Polignac number, because 1020111221 - 2²⁶ = 953002357 is a prime.

It is a super-2 number, since 2×1020111221² = 2081253806420221682, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1020113221) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17588096 + ... + 17588153.

It is an arithmetic number, because the mean of its divisors is an integer number (263821875).

Almost surely, 2^1020111221 is an apocalyptic number.

It is an amenable number.

1020111221 is a deficient number, since it is larger than the sum of its proper divisors (35176279).

1020111221 is an equidigital number, since it uses as much as digits as its factorization.

1020111221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35176278.

The product of its (nonzero) digits is 8, while the sum is 11.

The square root of 1020111221 is about 31939.1800301761. The cubic root of 1020111221 is about 1006.6592956762.

Adding to 1020111221 its reverse (1221110201), we get a palindrome (2241221422).

The spelling of 1020111221 in words is "one billion, twenty million, one hundred eleven thousand, two hundred twenty-one".