1121205649 has 2 divisors, whose sum is σ = 1121205650. Its totient is φ = 1121205648.

The previous prime is 1121205647. The next prime is 1121205661. The reversal of 1121205649 is 9465021211.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 949071249 + 172134400 = 30807^2 + 13120^2 .

It is a cyclic number.

It is not a de Polignac number, because 1121205649 - 2¹ = 1121205647 is a prime.

It is a super-2 number, since 2×1121205649² = 2514204214699022402, which contains 22 as substring.

Together with 1121205647, 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 1121205649.

It is not a weakly prime, because it can be changed into another prime (1121205647) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 560602824 + 560602825.

It is an arithmetic number, because the mean of its divisors is an integer number (560602825).

Almost surely, 2^1121205649 is an apocalyptic number.

It is an amenable number.

1121205649 is a deficient number, since it is larger than the sum of its proper divisors (1).

1121205649 is an equidigital number, since it uses as much as digits as its factorization.

1121205649 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4320, while the sum is 31.

The square root of 1121205649 is about 33484.4090436131. The cubic root of 1121205649 is about 1038.8713251505.

The spelling of 1121205649 in words is "one billion, one hundred twenty-one million, two hundred five thousand, six hundred forty-nine".