1197815987 has 2 divisors, whose sum is σ = 1197815988. Its totient is φ = 1197815986.

The previous prime is 1197815977. The next prime is 1197815989. The reversal of 1197815987 is 7895187911.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1197815987 - 2¹⁶ = 1197750451 is a prime.

Together with 1197815989, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1197815989) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 598907993 + 598907994.

It is an arithmetic number, because the mean of its divisors is an integer number (598907994).

Almost surely, 2^1197815987 is an apocalyptic number.

1197815987 is a deficient number, since it is larger than the sum of its proper divisors (1).

1197815987 is an equidigital number, since it uses as much as digits as its factorization.

1197815987 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1270080, while the sum is 56.

The square root of 1197815987 is about 34609.4782826901. The cubic root of 1197815987 is about 1062.0134943071.

The spelling of 1197815987 in words is "one billion, one hundred ninety-seven million, eight hundred fifteen thousand, nine hundred eighty-seven".