1321520407 has 4 divisors (see below), whose sum is σ = 1378977840. Its totient is φ = 1264062976.

The previous prime is 1321520393. The next prime is 1321520411. The reversal of 1321520407 is 7040251231.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1321520407 is a prime.

It is a super-2 number, since 2×1321520407² = 3492832372234891298, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1321520437) 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, 28728682 + ... + 28728727.

It is an arithmetic number, because the mean of its divisors is an integer number (344744460).

Almost surely, 2^1321520407 is an apocalyptic number.

1321520407 is a deficient number, since it is larger than the sum of its proper divisors (57457433).

1321520407 is an equidigital number, since it uses as much as digits as its factorization.

1321520407 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57457432.

The product of its (nonzero) digits is 1680, while the sum is 25.

The square root of 1321520407 is about 36352.7221401644. The cubic root of 1321520407 is about 1097.3823174858.

Adding to 1321520407 its reverse (7040251231), we get a palindrome (8361771638).

The spelling of 1321520407 in words is "one billion, three hundred twenty-one million, five hundred twenty thousand, four hundred seven".