1221055125405 has 16 divisors (see below), whose sum is σ = 1977226614720. Its totient is φ = 643383262208.

The previous prime is 1221055125373. The next prime is 1221055125431. The reversal of 1221055125405 is 5045215501221.

It is a cyclic number.

It is not a de Polignac number, because 1221055125405 - 2⁵ = 1221055125373 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 490382340 + ... + 490384829.

It is an arithmetic number, because the mean of its divisors is an integer number (123576663420).

Almost surely, 2^{1221055125405} is an apocalyptic number.

1221055125405 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1221055125405 is a deficient number, since it is larger than the sum of its proper divisors (756171489315).

1221055125405 is an equidigital number, since it uses as much as digits as its factorization.

1221055125405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 980767260.

The product of its (nonzero) digits is 20000, while the sum is 33.

The spelling of 1221055125405 in words is "one trillion, two hundred twenty-one billion, fifty-five million, one hundred twenty-five thousand, four hundred five".