1321121523 has 4 divisors (see below), whose sum is σ = 1761495368. Its totient is φ = 880747680.

The previous prime is 1321121497. The next prime is 1321121563. The reversal of 1321121523 is 3251211231.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 1321121523 - 2⁸ = 1321121267 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 1321121523.

It is not an unprimeable number, because it can be changed into a prime (1321121563) 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, 220186918 + ... + 220186923.

It is an arithmetic number, because the mean of its divisors is an integer number (440373842).

Almost surely, 2^1321121523 is an apocalyptic number.

1321121523 is a deficient number, since it is larger than the sum of its proper divisors (440373845).

1321121523 is an equidigital number, since it uses as much as digits as its factorization.

1321121523 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 440373844.

The product of its digits is 360, while the sum is 21.

The square root of 1321121523 is about 36347.2354244446. The cubic root of 1321121523 is about 1097.2718961119.

Adding to 1321121523 its reverse (3251211231), we get a palindrome (4572332754).

The spelling of 1321121523 in words is "one billion, three hundred twenty-one million, one hundred twenty-one thousand, five hundred twenty-three".