1231421855205 has 8 divisors (see below), whose sum is σ = 1970274968352. Its totient is φ = 656758322768.

The previous prime is 1231421855177. The next prime is 1231421855233. The reversal of 1231421855205 is 5025581241321.

It is an interprime number because it is at equal distance from previous prime (1231421855177) and next prime (1231421855233).

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 1231421855205 - 2¹⁰ = 1231421854181 is a prime.

It is a congruent number.

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, 41047395159 + ... + 41047395188.

It is an arithmetic number, because the mean of its divisors is an integer number (246284371044).

Almost surely, 2^{1231421855205} is an apocalyptic number.

1231421855205 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1231421855205 is a deficient number, since it is larger than the sum of its proper divisors (738853113147).

1231421855205 is an equidigital number, since it uses as much as digits as its factorization.

1231421855205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82094790355.

The product of its (nonzero) digits is 96000, while the sum is 39.

The spelling of 1231421855205 in words is "one trillion, two hundred thirty-one billion, four hundred twenty-one million, eight hundred fifty-five thousand, two hundred five".