1621886855 has 4 divisors (see below), whose sum is σ = 1946264232. Its totient is φ = 1297509480.

The previous prime is 1621886843. The next prime is 1621886891. The reversal of 1621886855 is 5586881261.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 1621886855 - 2⁴ = 1621886839 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 162188681 + ... + 162188690.

It is an arithmetic number, because the mean of its divisors is an integer number (486566058).

Almost surely, 2^1621886855 is an apocalyptic number.

1621886855 is a deficient number, since it is larger than the sum of its proper divisors (324377377).

1621886855 is an equidigital number, since it uses as much as digits as its factorization.

1621886855 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 324377376.

The product of its digits is 921600, while the sum is 50.

The square root of 1621886855 is about 40272.6564184684. The cubic root of 1621886855 is about 1174.9160899789.

The spelling of 1621886855 in words is "one billion, six hundred twenty-one million, eight hundred eighty-six thousand, eight hundred fifty-five".