1815232997 has 2 divisors, whose sum is σ = 1815232998. Its totient is φ = 1815232996.

The previous prime is 1815232973. The next prime is 1815233009. The reversal of 1815232997 is 7992325181.

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., 1681738081 + 133494916 = 41009^2 + 11554^2 .

It is an emirp because it is prime and its reverse (7992325181) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1815232997 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1815232597) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 907616498 + 907616499.

It is an arithmetic number, because the mean of its divisors is an integer number (907616499).

Almost surely, 2^1815232997 is an apocalyptic number.

It is an amenable number.

1815232997 is a deficient number, since it is larger than the sum of its proper divisors (1).

1815232997 is an equidigital number, since it uses as much as digits as its factorization.

1815232997 is an evil number, because the sum of its binary digits is even.

The product of its digits is 272160, while the sum is 47.

The square root of 1815232997 is about 42605.5512462871. The cubic root of 1815232997 is about 1219.8622519833.

The spelling of 1815232997 in words is "one billion, eight hundred fifteen million, two hundred thirty-two thousand, nine hundred ninety-seven".