15372821 has 2 divisors, whose sum is σ = 15372822. Its totient is φ = 15372820.

The previous prime is 15372803. The next prime is 15372823. The reversal of 15372821 is 12827351.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14668900 + 703921 = 3830^2 + 839^2 .

It is a cyclic number.

It is not a de Polignac number, because 15372821 - 2¹⁸ = 15110677 is a prime.

It is a Sophie Germain prime.

Together with 15372823, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15372823) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7686410 + 7686411.

It is an arithmetic number, because the mean of its divisors is an integer number (7686411).

Almost surely, 2^15372821 is an apocalyptic number.

It is an amenable number.

15372821 is a deficient number, since it is larger than the sum of its proper divisors (1).

15372821 is an equidigital number, since it uses as much as digits as its factorization.

15372821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3360, while the sum is 29.

The square root of 15372821 is about 3920.8189195626. The cubic root of 15372821 is about 248.6477441376.

The spelling of 15372821 in words is "fifteen million, three hundred seventy-two thousand, eight hundred twenty-one".