1021320121 has 4 divisors (see below), whose sum is σ = 1027026000. Its totient is φ = 1015614244.

The previous prime is 1021320107. The next prime is 1021320143. The reversal of 1021320121 is 1210231201.

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 a cyclic number.

It is not a de Polignac number, because 1021320121 - 2⁵ = 1021320089 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1021320191) 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, 2852671 + ... + 2853028.

It is an arithmetic number, because the mean of its divisors is an integer number (256756500).

Almost surely, 2^1021320121 is an apocalyptic number.

It is an amenable number.

1021320121 is a deficient number, since it is larger than the sum of its proper divisors (5705879).

1021320121 is an equidigital number, since it uses as much as digits as its factorization.

1021320121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5705878.

The product of its (nonzero) digits is 24, while the sum is 13.

The square root of 1021320121 is about 31958.0994585097. The cubic root of 1021320121 is about 1007.0567915542.

Adding to 1021320121 its reverse (1210231201), we get a palindrome (2231551322).

The spelling of 1021320121 in words is "one billion, twenty-one million, three hundred twenty thousand, one hundred twenty-one".