1261332505 has 8 divisors (see below), whose sum is σ = 1523240712. Its totient is φ = 1002638208.

The previous prime is 1261332497. The next prime is 1261332511. The reversal of 1261332505 is 5052331621.

It can be written as a sum of positive squares in 4 ways, for example, as 119771136 + 1141561369 = 10944^2 + 33787^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1261332505 - 2³ = 1261332497 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 802612 + ... + 804181.

It is an arithmetic number, because the mean of its divisors is an integer number (190405089).

Almost surely, 2^1261332505 is an apocalyptic number.

It is an amenable number.

1261332505 is a deficient number, since it is larger than the sum of its proper divisors (261908207).

1261332505 is a wasteful number, since it uses less digits than its factorization.

1261332505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1606955.

The product of its (nonzero) digits is 5400, while the sum is 28.

The square root of 1261332505 is about 35515.2432766552. The cubic root of 1261332505 is about 1080.4629088417.

The spelling of 1261332505 in words is "one billion, two hundred sixty-one million, three hundred thirty-two thousand, five hundred five".