1640727899 has 2 divisors, whose sum is σ = 1640727900. Its totient is φ = 1640727898.

The previous prime is 1640727863. The next prime is 1640727901. The reversal of 1640727899 is 9987270461.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1640727899 - 2⁸ = 1640727643 is a prime.

Together with 1640727901, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1640727899.

It is not a weakly prime, because it can be changed into another prime (1640727799) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 820363949 + 820363950.

It is an arithmetic number, because the mean of its divisors is an integer number (820363950).

Almost surely, 2^1640727899 is an apocalyptic number.

1640727899 is a deficient number, since it is larger than the sum of its proper divisors (1).

1640727899 is an equidigital number, since it uses as much as digits as its factorization.

1640727899 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1524096, while the sum is 53.

The square root of 1640727899 is about 40505.8995579656. The cubic root of 1640727899 is about 1179.4481521379.

The spelling of 1640727899 in words is "one billion, six hundred forty million, seven hundred twenty-seven thousand, eight hundred ninety-nine".