1565361261 has 8 divisors (see below), whose sum is σ = 2319053760. Its totient is φ = 1043574156.

The previous prime is 1565361223. The next prime is 1565361271. The reversal of 1565361261 is 1621635651.

1565361261 is a `hidden beast` number, since 1 + 56 + 536 + 12 + 61 = 666.

It is a de Polignac number, because none of the positive numbers 2^k-1565361261 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1565361271) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28988145 + ... + 28988198.

It is an arithmetic number, because the mean of its divisors is an integer number (289881720).

Almost surely, 2^1565361261 is an apocalyptic number.

It is an amenable number.

1565361261 is a deficient number, since it is larger than the sum of its proper divisors (753692499).

1565361261 is an equidigital number, since it uses as much as digits as its factorization.

1565361261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57976352 (or 57976346 counting only the distinct ones).

The product of its digits is 32400, while the sum is 36.

The square root of 1565361261 is about 39564.6466052712. The cubic root of 1565361261 is about 1161.1050856680.

The spelling of 1565361261 in words is "one billion, five hundred sixty-five million, three hundred sixty-one thousand, two hundred sixty-one".