1641405818 has 16 divisors (see below), whose sum is σ = 2681297640. Its totient is φ = 749058816.

The previous prime is 1641405797. The next prime is 1641405827. The reversal of 1641405818 is 8185041461.

It can be written as a sum of positive squares in 4 ways, for example, as 696273769 + 945132049 = 26387^2 + 30743^2 .

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 352355 + ... + 356982.

Almost surely, 2^1641405818 is an apocalyptic number.

1641405818 is a deficient number, since it is larger than the sum of its proper divisors (1039891822).

1641405818 is a wasteful number, since it uses less digits than its factorization.

1641405818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 709441.

The product of its (nonzero) digits is 30720, while the sum is 38.

The square root of 1641405818 is about 40514.2668451497. The cubic root of 1641405818 is about 1179.6105719628.

The spelling of 1641405818 in words is "one billion, six hundred forty-one million, four hundred five thousand, eight hundred eighteen".