645428029 has 4 divisors (see below), whose sum is σ = 666248320. Its totient is φ = 624607740.

The previous prime is 645428023. The next prime is 645428051. The reversal of 645428029 is 920824546.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 645428029 - 2⁷ = 645427901 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 645427982 and 645428000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645428023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10410099 + ... + 10410160.

It is an arithmetic number, because the mean of its divisors is an integer number (166562080).

Almost surely, 2^645428029 is an apocalyptic number.

It is an amenable number.

645428029 is a deficient number, since it is larger than the sum of its proper divisors (20820291).

645428029 is a wasteful number, since it uses less digits than its factorization.

645428029 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20820290.

The product of its (nonzero) digits is 138240, while the sum is 40.

The square root of 645428029 is about 25405.2756135414. The cubic root of 645428029 is about 864.2033401472.

The spelling of 645428029 in words is "six hundred forty-five million, four hundred twenty-eight thousand, twenty-nine".