1815397 has 2 divisors, whose sum is σ = 1815398. Its totient is φ = 1815396.

The previous prime is 1815389. The next prime is 1815403. The reversal of 1815397 is 7935181.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1758276 + 57121 = 1326^2 + 239^2 .

It is a cyclic number.

It is not a de Polignac number, because 1815397 - 2³ = 1815389 is a prime.

1815397 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1815337) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 907698 + 907699.

It is an arithmetic number, because the mean of its divisors is an integer number (907699).

2^1815397 is an apocalyptic number.

It is an amenable number.

1815397 is a deficient number, since it is larger than the sum of its proper divisors (1).

1815397 is an equidigital number, since it uses as much as digits as its factorization.

1815397 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7560, while the sum is 34.

The square root of 1815397 is about 1347.3666909940. The cubic root of 1815397 is about 121.9898988322.

The spelling of 1815397 in words is "one million, eight hundred fifteen thousand, three hundred ninety-seven".