1261631222 has 16 divisors (see below), whose sum is σ = 1911725712. Its totient is φ = 624399360.

The previous prime is 1261631221. The next prime is 1261631243. The reversal of 1261631222 is 2221361621.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 1261631191 and 1261631200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1261631221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 443918 + ... + 446750.

It is an arithmetic number, because the mean of its divisors is an integer number (119482857).

Almost surely, 2^1261631222 is an apocalyptic number.

1261631222 is a deficient number, since it is larger than the sum of its proper divisors (650094490).

1261631222 is a wasteful number, since it uses less digits than its factorization.

1261631222 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5023.

The product of its digits is 1728, while the sum is 26.

The square root of 1261631222 is about 35519.4485036015. The cubic root of 1261631222 is about 1080.5481962030.

Adding to 1261631222 its reverse (2221361621), we get a palindrome (3482992843).

The spelling of 1261631222 in words is "one billion, two hundred sixty-one million, six hundred thirty-one thousand, two hundred twenty-two".