645507071 has 8 divisors (see below), whose sum is σ = 719172864. Its totient is φ = 574338520.

The previous prime is 645507061. The next prime is 645507073. The reversal of 645507071 is 170705546.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 645507071 - 2²⁶ = 578398207 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645507073) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 623765 + ... + 624798.

It is an arithmetic number, because the mean of its divisors is an integer number (89896608).

Almost surely, 2^645507071 is an apocalyptic number.

645507071 is a deficient number, since it is larger than the sum of its proper divisors (73665793).

645507071 is a wasteful number, since it uses less digits than its factorization.

645507071 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1248621.

The product of its (nonzero) digits is 29400, while the sum is 35.

The square root of 645507071 is about 25406.8311876944. The cubic root of 645507071 is about 864.2386167746.

The spelling of 645507071 in words is "six hundred forty-five million, five hundred seven thousand, seventy-one".