645120005 has 8 divisors (see below), whose sum is σ = 775440000. Its totient is φ = 515232016.

The previous prime is 645119947. The next prime is 645120023. The reversal of 645120005 is 500021546.

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 645120005 - 2¹⁶ = 645054469 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 104705 + ... + 110694.

It is an arithmetic number, because the mean of its divisors is an integer number (96930000).

Almost surely, 2^645120005 is an apocalyptic number.

It is an amenable number.

645120005 is a deficient number, since it is larger than the sum of its proper divisors (130319995).

645120005 is a wasteful number, since it uses less digits than its factorization.

645120005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 216003.

The product of its (nonzero) digits is 1200, while the sum is 23.

The square root of 645120005 is about 25399.2126846483. The cubic root of 645120005 is about 864.0658408365.

The spelling of 645120005 in words is "six hundred forty-five million, one hundred twenty thousand, five".