645542999 has 2 divisors, whose sum is σ = 645543000. Its totient is φ = 645542998.

The previous prime is 645542983. The next prime is 645543029. The reversal of 645542999 is 999245546.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 645542999 - 2⁴ = 645542983 is a prime.

It is a Chen prime.

It is a zygodrome in base 3.

It is a self number, because there is not a number n which added to its sum of digits gives 645542999.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (645542939) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322771499 + 322771500.

It is an arithmetic number, because the mean of its divisors is an integer number (322771500).

Almost surely, 2^645542999 is an apocalyptic number.

645542999 is a deficient number, since it is larger than the sum of its proper divisors (1).

645542999 is an equidigital number, since it uses as much as digits as its factorization.

645542999 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3499200, while the sum is 53.

The square root of 645542999 is about 25407.5382317925. The cubic root of 645542999 is about 864.2546505720.

The spelling of 645542999 in words is "six hundred forty-five million, five hundred forty-two thousand, nine hundred ninety-nine".