1855421641 has 4 divisors (see below), whose sum is σ = 1915273984. Its totient is φ = 1795569300.

The previous prime is 1855421627. The next prime is 1855421651. The reversal of 1855421641 is 1461245581.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1855421641 - 2¹³ = 1855413449 is a prime.

It is a super-2 number, since 2×1855421641² = 6885178931782265762, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1855421641.

It is not an unprimeable number, because it can be changed into a prime (1855421651) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 29926125 + ... + 29926186.

It is an arithmetic number, because the mean of its divisors is an integer number (478818496).

Almost surely, 2^1855421641 is an apocalyptic number.

It is an amenable number.

1855421641 is a deficient number, since it is larger than the sum of its proper divisors (59852343).

1855421641 is an equidigital number, since it uses as much as digits as its factorization.

1855421641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 59852342.

The product of its digits is 38400, while the sum is 37.

The square root of 1855421641 is about 43074.6055234404. The cubic root of 1855421641 is about 1228.7990660007.

The spelling of 1855421641 in words is "one billion, eight hundred fifty-five million, four hundred twenty-one thousand, six hundred forty-one".