1221563633 has 2 divisors, whose sum is σ = 1221563634. Its totient is φ = 1221563632.

The previous prime is 1221563593. The next prime is 1221563641. The reversal of 1221563633 is 3363651221.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1012703329 + 208860304 = 31823^2 + 14452^2 .

It is a cyclic number.

It is not a de Polignac number, because 1221563633 - 2⁶ = 1221563569 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1221563633.

It is not a weakly prime, because it can be changed into another prime (1221563683) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610781816 + 610781817.

It is an arithmetic number, because the mean of its divisors is an integer number (610781817).

Almost surely, 2^1221563633 is an apocalyptic number.

It is an amenable number.

1221563633 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221563633 is an equidigital number, since it uses as much as digits as its factorization.

1221563633 is an evil number, because the sum of its binary digits is even.

The product of its digits is 19440, while the sum is 32.

The square root of 1221563633 is about 34950.8745670262. The cubic root of 1221563633 is about 1068.9860348094.

The spelling of 1221563633 in words is "one billion, two hundred twenty-one million, five hundred sixty-three thousand, six hundred thirty-three".