1021311221 has 4 divisors (see below), whose sum is σ = 1167212832. Its totient is φ = 875409612.

The previous prime is 1021311211. The next prime is 1021311281. The reversal of 1021311221 is 1221131201.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 1021311221 - 2¹⁴ = 1021294837 is a prime.

It is a super-2 number, since 2×1021311221² = 2086153220281021682, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1021311196 and 1021311205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1021311211) 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, 72950795 + ... + 72950808.

It is an arithmetic number, because the mean of its divisors is an integer number (291803208).

Almost surely, 2^1021311221 is an apocalyptic number.

It is an amenable number.

1021311221 is a deficient number, since it is larger than the sum of its proper divisors (145901611).

1021311221 is an equidigital number, since it uses as much as digits as its factorization.

1021311221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 145901610.

The product of its (nonzero) digits is 24, while the sum is 14.

The square root of 1021311221 is about 31957.9602133803. The cubic root of 1021311221 is about 1007.0538663103.

Adding to 1021311221 its reverse (1221131201), we get a palindrome (2242442422).

The spelling of 1021311221 in words is "one billion, twenty-one million, three hundred eleven thousand, two hundred twenty-one".