645444152 has 8 divisors (see below), whose sum is σ = 1210207800. Its totient is φ = 322722072.

The previous prime is 645444139. The next prime is 645444157. The reversal of 645444152 is 251444546.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645444157) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40340252 + ... + 40340267.

It is an arithmetic number, because the mean of its divisors is an integer number (151275975).

Almost surely, 2^645444152 is an apocalyptic number.

It is an amenable number.

645444152 is a deficient number, since it is larger than the sum of its proper divisors (564763648).

645444152 is a wasteful number, since it uses less digits than its factorization.

645444152 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80680525 (or 80680521 counting only the distinct ones).

The product of its digits is 76800, while the sum is 35.

The square root of 645444152 is about 25405.5929275425. The cubic root of 645444152 is about 864.2105361132.

Adding to 645444152 its reverse (251444546), we get a palindrome (896888698).

The spelling of 645444152 in words is "six hundred forty-five million, four hundred forty-four thousand, one hundred fifty-two".