1213187999 has 2 divisors, whose sum is σ = 1213188000. Its totient is φ = 1213187998.

The previous prime is 1213187971. The next prime is 1213188013. The reversal of 1213187999 is 9997813121.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1213187999 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1213187959) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 606593999 + 606594000.

It is an arithmetic number, because the mean of its divisors is an integer number (606594000).

Almost surely, 2^1213187999 is an apocalyptic number.

1213187999 is a deficient number, since it is larger than the sum of its proper divisors (1).

1213187999 is an equidigital number, since it uses as much as digits as its factorization.

1213187999 is an evil number, because the sum of its binary digits is even.

The product of its digits is 244944, while the sum is 50.

The square root of 1213187999 is about 34830.8483818583. The cubic root of 1213187999 is about 1066.5372669960.

The spelling of 1213187999 in words is "one billion, two hundred thirteen million, one hundred eighty-seven thousand, nine hundred ninety-nine".