15321001 has 2 divisors, whose sum is σ = 15321002. Its totient is φ = 15321000.

The previous prime is 15320999. The next prime is 15321017. The reversal of 15321001 is 10012351.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13682601 + 1638400 = 3699^2 + 1280^2 .

It is an emirp because it is prime and its reverse (10012351) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 15321001 - 2¹ = 15320999 is a prime.

Together with 15320999, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (15321041) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7660500 + 7660501.

It is an arithmetic number, because the mean of its divisors is an integer number (7660501).

Almost surely, 2^15321001 is an apocalyptic number.

It is an amenable number.

15321001 is a deficient number, since it is larger than the sum of its proper divisors (1).

15321001 is an equidigital number, since it uses as much as digits as its factorization.

15321001 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 30, while the sum is 13.

The square root of 15321001 is about 3914.2050278441. The cubic root of 15321001 is about 248.3680420334.

Adding to 15321001 its reverse (10012351), we get a palindrome (25333352).

The spelling of 15321001 in words is "fifteen million, three hundred twenty-one thousand, one".