1261245345 has 16 divisors (see below), whose sum is σ = 2018511360. Its totient is φ = 672491264.

The previous prime is 1261245331. The next prime is 1261245347. The reversal of 1261245345 is 5435421621.

It is a cyclic number.

It is not a de Polignac number, because 1261245345 - 2¹⁰ = 1261244321 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1261245347) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 68041 + ... + 84569.

It is an arithmetic number, because the mean of its divisors is an integer number (126156960).

Almost surely, 2^1261245345 is an apocalyptic number.

1261245345 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1261245345 is a deficient number, since it is larger than the sum of its proper divisors (757266015).

1261245345 is a wasteful number, since it uses less digits than its factorization.

1261245345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21624.

The product of its digits is 28800, while the sum is 33.

The square root of 1261245345 is about 35514.0161767154. The cubic root of 1261245345 is about 1080.4380210567.

Adding to 1261245345 its reverse (5435421621), we get a palindrome (6696666966).

The spelling of 1261245345 in words is "one billion, two hundred sixty-one million, two hundred forty-five thousand, three hundred forty-five".