1261817120 has 24 divisors (see below), whose sum is σ = 2981043324. Its totient is φ = 504726784.

The previous prime is 1261817101. The next prime is 1261817201. The reversal of 1261817120 is 217181621.

It can be written as a sum of positive squares in 2 ways, for example, as 1194117136 + 67699984 = 34556^2 + 8228^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3943019 + ... + 3943338.

Almost surely, 2^1261817120 is an apocalyptic number.

1261817120 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1261817120 is an abundant number, since it is smaller than the sum of its proper divisors (1719226204).

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

1261817120 is an equidigital number, since it uses as much as digits as its factorization.

1261817120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7886372 (or 7886364 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 29.

The square root of 1261817120 is about 35522.0652552748. The cubic root of 1261817120 is about 1080.6012655627.

Adding to 1261817120 its reverse (217181621), we get a palindrome (1478998741).

The spelling of 1261817120 in words is "one billion, two hundred sixty-one million, eight hundred seventeen thousand, one hundred twenty".