1221793663 has 2 divisors, whose sum is σ = 1221793664. Its totient is φ = 1221793662.

The previous prime is 1221793633. The next prime is 1221793673. The reversal of 1221793663 is 3663971221.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1221793663 - 2⁹ = 1221793151 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1221793633) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610896831 + 610896832.

It is an arithmetic number, because the mean of its divisors is an integer number (610896832).

Almost surely, 2^1221793663 is an apocalyptic number.

1221793663 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221793663 is an equidigital number, since it uses as much as digits as its factorization.

1221793663 is an evil number, because the sum of its binary digits is even.

The product of its digits is 81648, while the sum is 40.

The square root of 1221793663 is about 34954.1651738387. The cubic root of 1221793663 is about 1069.0531300791.

The spelling of 1221793663 in words is "one billion, two hundred twenty-one million, seven hundred ninety-three thousand, six hundred sixty-three".