1211553647 has 2 divisors, whose sum is σ = 1211553648. Its totient is φ = 1211553646.

The previous prime is 1211553611. The next prime is 1211553653. The reversal of 1211553647 is 7463551121.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1211553647 - 2¹⁶ = 1211488111 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1211553667) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 605776823 + 605776824.

It is an arithmetic number, because the mean of its divisors is an integer number (605776824).

Almost surely, 2^1211553647 is an apocalyptic number.

1211553647 is a deficient number, since it is larger than the sum of its proper divisors (1).

1211553647 is an equidigital number, since it uses as much as digits as its factorization.

1211553647 is an evil number, because the sum of its binary digits is even.

The product of its digits is 25200, while the sum is 35.

The square root of 1211553647 is about 34807.3792032667. The cubic root of 1211553647 is about 1066.0581215149.

The spelling of 1211553647 in words is "one billion, two hundred eleven million, five hundred fifty-three thousand, six hundred forty-seven".