1321513541 has 4 divisors (see below), whose sum is σ = 1324964352. Its totient is φ = 1318062732.

The previous prime is 1321513537. The next prime is 1321513559. The reversal of 1321513541 is 1453151231.

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, and also an emirpimes, since its reverse is a distinct semiprime: 1453151231 = 7 ⋅207593033.

It is a cyclic number.

It is not a de Polignac number, because 1321513541 - 2² = 1321513537 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 1321513541.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1321513511) 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, 1724831 + ... + 1725596.

It is an arithmetic number, because the mean of its divisors is an integer number (331241088).

Almost surely, 2^1321513541 is an apocalyptic number.

It is an amenable number.

1321513541 is a deficient number, since it is larger than the sum of its proper divisors (3450811).

1321513541 is an equidigital number, since it uses as much as digits as its factorization.

1321513541 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3450810.

The product of its digits is 1800, while the sum is 26.

The square root of 1321513541 is about 36352.6277041977. The cubic root of 1321513541 is about 1097.3804169879.

Adding to 1321513541 its reverse (1453151231), we get a palindrome (2774664772).

The spelling of 1321513541 in words is "one billion, three hundred twenty-one million, five hundred thirteen thousand, five hundred forty-one".