1321538401 has 16 divisors (see below), whose sum is σ = 1449681408. Its totient is φ = 1199289600.

The previous prime is 1321538389. The next prime is 1321538429. The reversal of 1321538401 is 1048351231.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 1321538401 - 2¹³ = 1321530209 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 1321538401.

It is not an unprimeable number, because it can be changed into a prime (1321538431) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 144711 + ... + 153571.

It is an arithmetic number, because the mean of its divisors is an integer number (90605088).

Almost surely, 2^1321538401 is an apocalyptic number.

It is an amenable number.

1321538401 is a deficient number, since it is larger than the sum of its proper divisors (128143007).

1321538401 is a wasteful number, since it uses less digits than its factorization.

1321538401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9192.

The product of its (nonzero) digits is 2880, while the sum is 28.

The square root of 1321538401 is about 36352.9696311044. The cubic root of 1321538401 is about 1097.3872981650.

Adding to 1321538401 its reverse (1048351231), we get a palindrome (2369889632).

The spelling of 1321538401 in words is "one billion, three hundred twenty-one million, five hundred thirty-eight thousand, four hundred one".