1221436761 has 16 divisors (see below), whose sum is σ = 1686495360. Its totient is φ = 785393280.

The previous prime is 1221436759. The next prime is 1221436817. The reversal of 1221436761 is 1676341221.

It is not a de Polignac number, because 1221436761 - 2¹ = 1221436759 is a prime.

It is a super-2 number, since 2×1221436761² = 2983815522244342242, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1221436061) 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, 83076 + ... + 96666.

It is an arithmetic number, because the mean of its divisors is an integer number (105405960).

Almost surely, 2^1221436761 is an apocalyptic number.

It is an amenable number.

1221436761 is a deficient number, since it is larger than the sum of its proper divisors (465058599).

1221436761 is a wasteful number, since it uses less digits than its factorization.

1221436761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14656.

The product of its digits is 12096, while the sum is 33.

The square root of 1221436761 is about 34949.0595152430. The cubic root of 1221436761 is about 1068.9490251146.

Adding to 1221436761 its reverse (1676341221), we get a palindrome (2897777982).

The spelling of 1221436761 in words is "one billion, two hundred twenty-one million, four hundred thirty-six thousand, seven hundred sixty-one".