1261409539 has 16 divisors (see below), whose sum is σ = 1419630912. Its totient is φ = 1112082048.

The previous prime is 1261409533. The next prime is 1261409573. The reversal of 1261409539 is 9359041621.

It is a cyclic number.

It is not a de Polignac number, because 1261409539 - 2³ = 1261409531 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1261409531) 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, 223557 + ... + 229129.

It is an arithmetic number, because the mean of its divisors is an integer number (88726932).

Almost surely, 2^1261409539 is an apocalyptic number.

1261409539 is a deficient number, since it is larger than the sum of its proper divisors (158221373).

1261409539 is a wasteful number, since it uses less digits than its factorization.

1261409539 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6366.

The product of its (nonzero) digits is 58320, while the sum is 40.

The square root of 1261409539 is about 35516.3277803322. The cubic root of 1261409539 is about 1080.4849042803.

The spelling of 1261409539 in words is "one billion, two hundred sixty-one million, four hundred nine thousand, five hundred thirty-nine".