645520094 has 4 divisors (see below), whose sum is σ = 968280144. Its totient is φ = 322760046.

The previous prime is 645520091. The next prime is 645520129. The reversal of 645520094 is 490025546.

It is a happy number.

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

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645520091) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 161380022 + ... + 161380025.

It is an arithmetic number, because the mean of its divisors is an integer number (242070036).

Almost surely, 2^645520094 is an apocalyptic number.

645520094 is a deficient number, since it is larger than the sum of its proper divisors (322760050).

645520094 is a wasteful number, since it uses less digits than its factorization.

645520094 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 322760049.

The product of its (nonzero) digits is 43200, while the sum is 35.

The square root of 645520094 is about 25407.0874757419. The cubic root of 645520094 is about 864.2444286932.

The spelling of 645520094 in words is "six hundred forty-five million, five hundred twenty thousand, ninety-four".