1261416561 has 8 divisors (see below), whose sum is σ = 1697319360. Its totient is φ = 833229072.

The previous prime is 1261416557. The next prime is 1261416613. The reversal of 1261416561 is 1656141621.

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

It is not a de Polignac number, because 1261416561 - 2² = 1261416557 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1261416511) 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, 1928445 + ... + 1929098.

It is an arithmetic number, because the mean of its divisors is an integer number (212164920).

Almost surely, 2^1261416561 is an apocalyptic number.

It is an amenable number.

1261416561 is a deficient number, since it is larger than the sum of its proper divisors (435902799).

1261416561 is a wasteful number, since it uses less digits than its factorization.

1261416561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3857655.

The product of its digits is 8640, while the sum is 33.

The square root of 1261416561 is about 35516.4266361356. The cubic root of 1261416561 is about 1080.4869092202.

The spelling of 1261416561 in words is "one billion, two hundred sixty-one million, four hundred sixteen thousand, five hundred sixty-one".