1640162891 has 2 divisors, whose sum is σ = 1640162892. Its totient is φ = 1640162890.

The previous prime is 1640162879. The next prime is 1640162903. The reversal of 1640162891 is 1982610461.

It is a balanced prime because it is at equal distance from previous prime (1640162879) and next prime (1640162903).

It is a cyclic number.

It is not a de Polignac number, because 1640162891 - 2⁶ = 1640162827 is a prime.

It is not a weakly prime, because it can be changed into another prime (1640162191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 820081445 + 820081446.

It is an arithmetic number, because the mean of its divisors is an integer number (820081446).

Almost surely, 2^1640162891 is an apocalyptic number.

1640162891 is a deficient number, since it is larger than the sum of its proper divisors (1).

1640162891 is an equidigital number, since it uses as much as digits as its factorization.

1640162891 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 20736, while the sum is 38.

The square root of 1640162891 is about 40498.9245659684. The cubic root of 1640162891 is about 1179.3127500091.

The spelling of 1640162891 in words is "one billion, six hundred forty million, one hundred sixty-two thousand, eight hundred ninety-one".