645562403 has 4 divisors (see below), whose sum is σ = 683536680. Its totient is φ = 607588128.

The previous prime is 645562399. The next prime is 645562453. The reversal of 645562403 is 304265546.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 645562403 - 2² = 645562399 is a prime.

It is not an unprimeable number, because it can be changed into a prime (645562453) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18987113 + ... + 18987146.

It is an arithmetic number, because the mean of its divisors is an integer number (170884170).

Almost surely, 2^645562403 is an apocalyptic number.

645562403 is a deficient number, since it is larger than the sum of its proper divisors (37974277).

645562403 is a wasteful number, since it uses less digits than its factorization.

645562403 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37974276.

The product of its (nonzero) digits is 86400, while the sum is 35.

The square root of 645562403 is about 25407.9200840998. The cubic root of 645562403 is about 864.2633098606.

The spelling of 645562403 in words is "six hundred forty-five million, five hundred sixty-two thousand, four hundred three".