1641987418 has 4 divisors (see below), whose sum is σ = 2462981130. Its totient is φ = 820993708.

The previous prime is 1641987383. The next prime is 1641987427. The reversal of 1641987418 is 8147891461.

It is a happy number.

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

It can be written as a sum of positive squares in only one way, i.e., 925193889 + 716793529 = 30417^2 + 26773^2 .

It is a super-2 number, since 2×1641987418² = 5392245361740613448, which contains 22 as substring.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

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 as a sum of consecutive naturals, namely, 410496853 + ... + 410496856.

Almost surely, 2^1641987418 is an apocalyptic number.

1641987418 is a deficient number, since it is larger than the sum of its proper divisors (820993712).

1641987418 is an equidigital number, since it uses as much as digits as its factorization.

1641987418 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 820993711.

The product of its digits is 387072, while the sum is 49.

The square root of 1641987418 is about 40521.4439278760. The cubic root of 1641987418 is about 1179.7498794772.

The spelling of 1641987418 in words is "one billion, six hundred forty-one million, nine hundred eighty-seven thousand, four hundred eighteen".