1641652891 has 2 divisors, whose sum is σ = 1641652892. Its totient is φ = 1641652890.

The previous prime is 1641652871. The next prime is 1641652907. The reversal of 1641652891 is 1982561461.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1641652891 is a prime.

It is not a weakly prime, because it can be changed into another prime (1641652871) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 820826445 + 820826446.

It is an arithmetic number, because the mean of its divisors is an integer number (820826446).

Almost surely, 2^1641652891 is an apocalyptic number.

1641652891 is a deficient number, since it is larger than the sum of its proper divisors (1).

1641652891 is an equidigital number, since it uses as much as digits as its factorization.

1641652891 is an evil number, because the sum of its binary digits is even.

The product of its digits is 103680, while the sum is 43.

The square root of 1641652891 is about 40517.3159402249. The cubic root of 1641652891 is about 1179.6697560471.

The spelling of 1641652891 in words is "one billion, six hundred forty-one million, six hundred fifty-two thousand, eight hundred ninety-one".