645515503 has 8 divisors (see below), whose sum is σ = 652948128. Its totient is φ = 638098944.

The previous prime is 645515491. The next prime is 645515509. The reversal of 645515503 is 305515546.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-645515503 is a prime.

It is a super-2 number, since 2×645515503² = 833380529226686018, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645515509) 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, 88950 + ... + 95932.

It is an arithmetic number, because the mean of its divisors is an integer number (81618516).

Almost surely, 2^645515503 is an apocalyptic number.

645515503 is a deficient number, since it is larger than the sum of its proper divisors (7432625).

645515503 is an equidigital number, since it uses as much as digits as its factorization.

645515503 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8033.

The product of its (nonzero) digits is 45000, while the sum is 34.

The square root of 645515503 is about 25406.9971267759. The cubic root of 645515503 is about 864.2423798257.

The spelling of 645515503 in words is "six hundred forty-five million, five hundred fifteen thousand, five hundred three".