1221342263 has 4 divisors (see below), whose sum is σ = 1239571320. Its totient is φ = 1203113208.

The previous prime is 1221342223. The next prime is 1221342277. The reversal of 1221342263 is 3622431221.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1221342263 is a prime.

It is a super-2 number, since 2×1221342263² = 2983353846779922338, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221342223) 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, 9114428 + ... + 9114561.

It is an arithmetic number, because the mean of its divisors is an integer number (309892830).

Almost surely, 2^1221342263 is an apocalyptic number.

1221342263 is a deficient number, since it is larger than the sum of its proper divisors (18229057).

1221342263 is an equidigital number, since it uses as much as digits as its factorization.

1221342263 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18229056.

The product of its digits is 3456, while the sum is 26.

The square root of 1221342263 is about 34947.7075499953. The cubic root of 1221342263 is about 1068.9214575392.

Adding to 1221342263 its reverse (3622431221), we get a palindrome (4843773484).

The spelling of 1221342263 in words is "one billion, two hundred twenty-one million, three hundred forty-two thousand, two hundred sixty-three".