1641001643 has 2 divisors, whose sum is σ = 1641001644. Its totient is φ = 1641001642.

The previous prime is 1641001591. The next prime is 1641001657. The reversal of 1641001643 is 3461001461.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1641001643 is a prime.

It is not a weakly prime, because it can be changed into another prime (1641001673) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 820500821 + 820500822.

It is an arithmetic number, because the mean of its divisors is an integer number (820500822).

Almost surely, 2^1641001643 is an apocalyptic number.

1641001643 is a deficient number, since it is larger than the sum of its proper divisors (1).

1641001643 is an equidigital number, since it uses as much as digits as its factorization.

1641001643 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1728, while the sum is 26.

The square root of 1641001643 is about 40509.2784803679. The cubic root of 1641001643 is about 1179.5137427214.

The spelling of 1641001643 in words is "one billion, six hundred forty-one million, one thousand, six hundred forty-three".