1640323247 has 2 divisors, whose sum is σ = 1640323248. Its totient is φ = 1640323246.

The previous prime is 1640323241. The next prime is 1640323271. The reversal of 1640323247 is 7423230461.

It is a weak prime.

It is an emirp because it is prime and its reverse (7423230461) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1640323247 - 2⁴ = 1640323231 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1640323241) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 820161623 + 820161624.

It is an arithmetic number, because the mean of its divisors is an integer number (820161624).

Almost surely, 2^1640323247 is an apocalyptic number.

1640323247 is a deficient number, since it is larger than the sum of its proper divisors (1).

1640323247 is an equidigital number, since it uses as much as digits as its factorization.

1640323247 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 24192, while the sum is 32.

The square root of 1640323247 is about 40500.9042738554. The cubic root of 1640323247 is about 1179.3511819059.

The spelling of 1640323247 in words is "one billion, six hundred forty million, three hundred twenty-three thousand, two hundred forty-seven".