1221481563 has 4 divisors (see below), whose sum is σ = 1628642088. Its totient is φ = 814321040.

The previous prime is 1221481559. The next prime is 1221481567. The reversal of 1221481563 is 3651841221.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (1221481559) and next prime (1221481567).

It is a cyclic number.

It is not a de Polignac number, because 1221481563 - 2² = 1221481559 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1221481567) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 203580258 + ... + 203580263.

It is an arithmetic number, because the mean of its divisors is an integer number (407160522).

Almost surely, 2^1221481563 is an apocalyptic number.

1221481563 is a deficient number, since it is larger than the sum of its proper divisors (407160525).

1221481563 is an equidigital number, since it uses as much as digits as its factorization.

1221481563 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 407160524.

The product of its digits is 11520, while the sum is 33.

The square root of 1221481563 is about 34949.7004708195. The cubic root of 1221481563 is about 1068.9620945506.

The spelling of 1221481563 in words is "one billion, two hundred twenty-one million, four hundred eighty-one thousand, five hundred sixty-three".