645448923 has 54 divisors (see below), whose sum is σ = 1121379012. Its totient is φ = 356695920.

The previous prime is 645448907. The next prime is 645448939. The reversal of 645448923 is 329844546.

645448923 is a `hidden beast` number, since 6 + 4 + 544 + 89 + 23 = 666.

It is an interprime number because it is at equal distance from previous prime (645448907) and next prime (645448939).

It is not a de Polignac number, because 645448923 - 2⁴ = 645448907 is a prime.

It is not an unprimeable number, because it can be changed into a prime (645448423) by changing a digit.

It is a polite number, since it can be written in 53 ways as a sum of consecutive naturals, for example, 423040 + ... + 424562.

It is an arithmetic number, because the mean of its divisors is an integer number (20766278).

Almost surely, 2^645448923 is an apocalyptic number.

645448923 is a gapful number since it is divisible by the number (63) formed by its first and last digit.

645448923 is a deficient number, since it is larger than the sum of its proper divisors (475930089).

645448923 is a wasteful number, since it uses less digits than its factorization.

645448923 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1605 (or 1564 counting only the distinct ones).

The product of its digits is 829440, while the sum is 45.

The square root of 645448923 is about 25405.6868240164. The cubic root of 645448923 is about 864.2126654677.

The spelling of 645448923 in words is "six hundred forty-five million, four hundred forty-eight thousand, nine hundred twenty-three".