1261831641 has 8 divisors (see below), whose sum is σ = 1922791104. Its totient is φ = 721046640.

The previous prime is 1261831639. The next prime is 1261831661. The reversal of 1261831641 is 1461381621.

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

It is not a de Polignac number, because 1261831641 - 2¹ = 1261831639 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1261831601) 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, 30043590 + ... + 30043631.

It is an arithmetic number, because the mean of its divisors is an integer number (240348888).

Almost surely, 2^1261831641 is an apocalyptic number.

It is an amenable number.

1261831641 is a deficient number, since it is larger than the sum of its proper divisors (660959463).

1261831641 is an equidigital number, since it uses as much as digits as its factorization.

1261831641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60087231.

The product of its digits is 6912, while the sum is 33.

The square root of 1261831641 is about 35522.2696487710. The cubic root of 1261831641 is about 1080.6054107357.

The spelling of 1261831641 in words is "one billion, two hundred sixty-one million, eight hundred thirty-one thousand, six hundred forty-one".