1189812649 has 2 divisors, whose sum is σ = 1189812650. Its totient is φ = 1189812648.

The previous prime is 1189812647. The next prime is 1189812671. The reversal of 1189812649 is 9462189811.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 992691049 + 197121600 = 31507^2 + 14040^2 .

It is a cyclic number.

It is not a de Polignac number, because 1189812649 - 2¹ = 1189812647 is a prime.

Together with 1189812647, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (1189812647) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 594906324 + 594906325.

It is an arithmetic number, because the mean of its divisors is an integer number (594906325).

Almost surely, 2^1189812649 is an apocalyptic number.

It is an amenable number.

1189812649 is a deficient number, since it is larger than the sum of its proper divisors (1).

1189812649 is an equidigital number, since it uses as much as digits as its factorization.

1189812649 is an evil number, because the sum of its binary digits is even.

The product of its digits is 248832, while the sum is 49.

The square root of 1189812649 is about 34493.6609973485. The cubic root of 1189812649 is about 1059.6428870004.

The spelling of 1189812649 in words is "one billion, one hundred eighty-nine million, eight hundred twelve thousand, six hundred forty-nine".