1261644105 has 8 divisors (see below), whose sum is σ = 2018630592. Its totient is φ = 672876848.

The previous prime is 1261644067. The next prime is 1261644113. The reversal of 1261644105 is 5014461621.

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 1261644105 - 2⁸ = 1261643849 is a prime.

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, 42054789 + ... + 42054818.

It is an arithmetic number, because the mean of its divisors is an integer number (252328824).

Almost surely, 2^1261644105 is an apocalyptic number.

1261644105 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1261644105 is a deficient number, since it is larger than the sum of its proper divisors (756986487).

1261644105 is an equidigital number, since it uses as much as digits as its factorization.

1261644105 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 84109615.

The product of its (nonzero) digits is 5760, while the sum is 30.

The square root of 1261644105 is about 35519.6298544903. The cubic root of 1261644105 is about 1080.5518741544.

The spelling of 1261644105 in words is "one billion, two hundred sixty-one million, six hundred forty-four thousand, one hundred five".