1261397875 has 32 divisors (see below), whose sum is σ = 1695245760. Its totient is φ = 933568000.

The previous prime is 1261397873. The next prime is 1261397899. The reversal of 1261397875 is 5787931621.

It is a happy number.

It is not a de Polignac number, because 1261397875 - 2¹ = 1261397873 is a prime.

It is a super-2 number, since 2×1261397875² = 3182249198109031250, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1261397873) 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 31 ways as a sum of consecutive naturals, for example, 120345 + ... + 130405.

It is an arithmetic number, because the mean of its divisors is an integer number (52976430).

Almost surely, 2^1261397875 is an apocalyptic number.

1261397875 is a deficient number, since it is larger than the sum of its proper divisors (433847885).

1261397875 is a wasteful number, since it uses less digits than its factorization.

1261397875 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10152 (or 10142 counting only the distinct ones).

The product of its digits is 635040, while the sum is 49.

The square root of 1261397875 is about 35516.1635737871. The cubic root of 1261397875 is about 1080.4815739280.

The spelling of 1261397875 in words is "one billion, two hundred sixty-one million, three hundred ninety-seven thousand, eight hundred seventy-five".