1321120421 has 4 divisors (see below), whose sum is σ = 1331523072. Its totient is φ = 1310717772.

The previous prime is 1321120399. The next prime is 1321120441. The reversal of 1321120421 is 1240211231.

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 1321120421 - 2³⁰ = 247378597 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1321120421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1321120441) 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, 5201135 + ... + 5201388.

It is an arithmetic number, because the mean of its divisors is an integer number (332880768).

Almost surely, 2^1321120421 is an apocalyptic number.

It is an amenable number.

1321120421 is a deficient number, since it is larger than the sum of its proper divisors (10402651).

1321120421 is a wasteful number, since it uses less digits than its factorization.

1321120421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10402650.

The product of its (nonzero) digits is 96, while the sum is 17.

The square root of 1321120421 is about 36347.2202651042. The cubic root of 1321120421 is about 1097.2715910191.

Adding to 1321120421 its reverse (1240211231), we get a palindrome (2561331652).

The spelling of 1321120421 in words is "one billion, three hundred twenty-one million, one hundred twenty thousand, four hundred twenty-one".