1640162191 has 2 divisors, whose sum is σ = 1640162192. Its totient is φ = 1640162190.

The previous prime is 1640162141. The next prime is 1640162203. The reversal of 1640162191 is 1912610461.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1640162191 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1640162141) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 820081095 + 820081096.

It is an arithmetic number, because the mean of its divisors is an integer number (820081096).

Almost surely, 2^1640162191 is an apocalyptic number.

1640162191 is a deficient number, since it is larger than the sum of its proper divisors (1).

1640162191 is an equidigital number, since it uses as much as digits as its factorization.

1640162191 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2592, while the sum is 31.

The square root of 1640162191 is about 40498.9159237627. The cubic root of 1640162191 is about 1179.3125822374.

The spelling of 1640162191 in words is "one billion, six hundred forty million, one hundred sixty-two thousand, one hundred ninety-one".