1277122221 has 48 divisors (see below), whose sum is σ = 2078935040. Its totient is φ = 780496560.

The previous prime is 1277122193. The next prime is 1277122241. The reversal of 1277122221 is 1222217721.

It is not a de Polignac number, because 1277122221 - 2²⁵ = 1243567789 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1277122241) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 138666 + ... + 147588.

Almost surely, 2^1277122221 is an apocalyptic number.

It is an amenable number.

1277122221 is a deficient number, since it is larger than the sum of its proper divisors (801812819).

1277122221 is an equidigital number, since it uses as much as digits as its factorization.

1277122221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8988 (or 8976 counting only the distinct ones).

The product of its digits is 1568, while the sum is 27.

The square root of 1277122221 is about 35736.8468250908. The cubic root of 1277122221 is about 1084.9527387797.

Adding to 1277122221 its reverse (1222217721), we get a palindrome (2499339942).

The spelling of 1277122221 in words is "one billion, two hundred seventy-seven million, one hundred twenty-two thousand, two hundred twenty-one".