1201511999 has 2 divisors, whose sum is σ = 1201512000. Its totient is φ = 1201511998.

The previous prime is 1201511951. The next prime is 1201512001. The reversal of 1201511999 is 9991151021.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1201511999 is a prime.

Together with 1201512001, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1201511939) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 600755999 + 600756000.

It is an arithmetic number, because the mean of its divisors is an integer number (600756000).

Almost surely, 2^1201511999 is an apocalyptic number.

1201511999 is a deficient number, since it is larger than the sum of its proper divisors (1).

1201511999 is an equidigital number, since it uses as much as digits as its factorization.

1201511999 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7290, while the sum is 38.

The square root of 1201511999 is about 34662.8331069461. The cubic root of 1201511999 is about 1063.1046981649.

The spelling of 1201511999 in words is "one billion, two hundred one million, five hundred eleven thousand, nine hundred ninety-nine".