1261145355 has 32 divisors (see below), whose sum is σ = 2082758400. Its totient is φ = 651311232.

The previous prime is 1261145351. The next prime is 1261145371. The reversal of 1261145355 is 5535411621.

It is not a de Polignac number, because 1261145355 - 2² = 1261145351 is a prime.

It is a super-3 number, since 3×1261145355³ (a number of 28 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (1261145351) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 48661 + ... + 69929.

It is an arithmetic number, because the mean of its divisors is an integer number (65086200).

Almost surely, 2^1261145355 is an apocalyptic number.

1261145355 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1261145355 is a deficient number, since it is larger than the sum of its proper divisors (821613045).

1261145355 is a wasteful number, since it uses less digits than its factorization.

1261145355 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21403.

The product of its digits is 18000, while the sum is 33.

The square root of 1261145355 is about 35512.6083947659. The cubic root of 1261145355 is about 1080.4094683639.

Adding to 1261145355 its reverse (5535411621), we get a palindrome (6796556976).

The spelling of 1261145355 in words is "one billion, two hundred sixty-one million, one hundred forty-five thousand, three hundred fifty-five".