1641818837 has 4 divisors (see below), whose sum is σ = 1664309580. Its totient is φ = 1619328096.

The previous prime is 1641818833. The next prime is 1641818851. The reversal of 1641818837 is 7388181461.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7388181461 = 373 ⋅19807457.

It can be written as a sum of positive squares in 2 ways, for example, as 1390469521 + 251349316 = 37289^2 + 15854^2 .

It is a cyclic number.

It is not a de Polignac number, because 1641818837 - 2² = 1641818833 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1641818791 and 1641818800.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1641818831) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11245262 + ... + 11245407.

It is an arithmetic number, because the mean of its divisors is an integer number (416077395).

Almost surely, 2^1641818837 is an apocalyptic number.

It is an amenable number.

1641818837 is a deficient number, since it is larger than the sum of its proper divisors (22490743).

1641818837 is an equidigital number, since it uses as much as digits as its factorization.

1641818837 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22490742.

The product of its digits is 258048, while the sum is 47.

The square root of 1641818837 is about 40519.3637289630. The cubic root of 1641818837 is about 1179.7095035647.

The spelling of 1641818837 in words is "one billion, six hundred forty-one million, eight hundred eighteen thousand, eight hundred thirty-seven".