1266322638 has 64 divisors (see below), whose sum is σ = 3094060032. Its totient is φ = 337624320.

The previous prime is 1266322573. The next prime is 1266322649. The reversal of 1266322638 is 8362236621.

It is a happy number.

It is a super-2 number, since 2×1266322638² = 3207146047022558088, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1266322596 and 1266322605.

It is a congruent number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 23620 + ... + 55592.

It is an arithmetic number, because the mean of its divisors is an integer number (48344688).

Almost surely, 2^1266322638 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1266322638, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1547030016).

1266322638 is an abundant number, since it is smaller than the sum of its proper divisors (1827737394).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1266322638 is a wasteful number, since it uses less digits than its factorization.

1266322638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32049.

The product of its digits is 124416, while the sum is 39.

The square root of 1266322638 is about 35585.4273263649. The cubic root of 1266322638 is about 1081.8858904790.

The spelling of 1266322638 in words is "one billion, two hundred sixty-six million, three hundred twenty-two thousand, six hundred thirty-eight".