1221517263 has 16 divisors (see below), whose sum is σ = 1666851840. Its totient is φ = 795337056.

The previous prime is 1221517261. The next prime is 1221517279. The reversal of 1221517263 is 3627151221.

It is not a de Polignac number, because 1221517263 - 2¹ = 1221517261 is a prime.

It is a super-2 number, since 2×1221517263² = 2984208847614022338, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1221517263.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221517261) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 59773 + ... + 77561.

It is an arithmetic number, because the mean of its divisors is an integer number (104178240).

Almost surely, 2^1221517263 is an apocalyptic number.

1221517263 is a deficient number, since it is larger than the sum of its proper divisors (445334577).

1221517263 is a wasteful number, since it uses less digits than its factorization.

1221517263 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18326.

The product of its digits is 5040, while the sum is 30.

The square root of 1221517263 is about 34950.2112010786. The cubic root of 1221517263 is about 1068.9725085637.

Adding to 1221517263 its reverse (3627151221), we get a palindrome (4848668484).

The spelling of 1221517263 in words is "one billion, two hundred twenty-one million, five hundred seventeen thousand, two hundred sixty-three".