645019807 has 2 divisors, whose sum is σ = 645019808. Its totient is φ = 645019806.

The previous prime is 645019789. The next prime is 645019811. The reversal of 645019807 is 708910546.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 645019807 - 2⁷ = 645019679 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 645019807.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (645019607) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322509903 + 322509904.

It is an arithmetic number, because the mean of its divisors is an integer number (322509904).

Almost surely, 2^645019807 is an apocalyptic number.

645019807 is a deficient number, since it is larger than the sum of its proper divisors (1).

645019807 is an equidigital number, since it uses as much as digits as its factorization.

645019807 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 60480, while the sum is 40.

The square root of 645019807 is about 25397.2401453386. The cubic root of 645019807 is about 864.0211038619.

The spelling of 645019807 in words is "six hundred forty-five million, nineteen thousand, eight hundred seven".