645421052 has 24 divisors (see below), whose sum is σ = 1136247840. Its totient is φ = 320785920.

The previous prime is 645421043. The next prime is 645421079. The reversal of 645421052 is 250124546.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 701849 + ... + 702767.

It is an arithmetic number, because the mean of its divisors is an integer number (47343660).

Almost surely, 2^645421052 is an apocalyptic number.

It is an amenable number.

645421052 is a deficient number, since it is larger than the sum of its proper divisors (490826788).

645421052 is a wasteful number, since it uses less digits than its factorization.

645421052 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1781 (or 1779 counting only the distinct ones).

The product of its (nonzero) digits is 9600, while the sum is 29.

The square root of 645421052 is about 25405.1382991709. The cubic root of 645421052 is about 864.2002261577.

Adding to 645421052 its reverse (250124546), we get a palindrome (895545598).

The spelling of 645421052 in words is "six hundred forty-five million, four hundred twenty-one thousand, fifty-two".