1201211509 has 2 divisors, whose sum is σ = 1201211510. Its totient is φ = 1201211508.

The previous prime is 1201211507. The next prime is 1201211513. The reversal of 1201211509 is 9051121021.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 649995025 + 551216484 = 25495^2 + 23478^2 .

It is a cyclic number.

It is not a de Polignac number, because 1201211509 - 2¹ = 1201211507 is a prime.

Together with 1201211507, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 1201211509.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1201211507) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 600605754 + 600605755.

It is an arithmetic number, because the mean of its divisors is an integer number (600605755).

Almost surely, 2^1201211509 is an apocalyptic number.

It is an amenable number.

1201211509 is a deficient number, since it is larger than the sum of its proper divisors (1).

1201211509 is an equidigital number, since it uses as much as digits as its factorization.

1201211509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 180, while the sum is 22.

The square root of 1201211509 is about 34658.4983662016. The cubic root of 1201211509 is about 1063.0160656847.

The spelling of 1201211509 in words is "one billion, two hundred one million, two hundred eleven thousand, five hundred nine".