1641672091 has 2 divisors, whose sum is σ = 1641672092. Its totient is φ = 1641672090.

The previous prime is 1641672083. The next prime is 1641672157. The reversal of 1641672091 is 1902761461.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1641672091 - 2³ = 1641672083 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1641672091.

It is not a weakly prime, because it can be changed into another prime (1641672001) by changing a digit.

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, 820836045 + 820836046.

It is an arithmetic number, because the mean of its divisors is an integer number (820836046).

Almost surely, 2^1641672091 is an apocalyptic number.

1641672091 is a deficient number, since it is larger than the sum of its proper divisors (1).

1641672091 is an equidigital number, since it uses as much as digits as its factorization.

1641672091 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18144, while the sum is 37.

The square root of 1641672091 is about 40517.5528752663. The cubic root of 1641672091 is about 1179.6743549833.

The spelling of 1641672091 in words is "one billion, six hundred forty-one million, six hundred seventy-two thousand, ninety-one".