1261438267 has 32 divisors (see below), whose sum is σ = 1432166400. Its totient is φ = 1105228800.

The previous prime is 1261438261. The next prime is 1261438271. The reversal of 1261438267 is 7628341621.

It is a de Polignac number, because none of the positive numbers 2^k-1261438267 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1261438261) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1706584 + ... + 1707322.

It is an arithmetic number, because the mean of its divisors is an integer number (44755200).

Almost surely, 2^1261438267 is an apocalyptic number.

1261438267 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

1261438267 is a deficient number, since it is larger than the sum of its proper divisors (170728133).

1261438267 is a wasteful number, since it uses less digits than its factorization.

1261438267 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 907.

The product of its digits is 96768, while the sum is 40.

The square root of 1261438267 is about 35516.7322117337. The cubic root of 1261438267 is about 1080.4931067274.

Adding to 1261438267 its reverse (7628341621), we get a palindrome (8889779888).

The spelling of 1261438267 in words is "one billion, two hundred sixty-one million, four hundred thirty-eight thousand, two hundred sixty-seven".