645192889 has 8 divisors (see below), whose sum is σ = 704083968. Its totient is φ = 586341360.

The previous prime is 645192839. The next prime is 645192917. The reversal of 645192889 is 988291546.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 645192889 - 2¹⁵ = 645160121 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (645192839) 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 7 ways as a sum of consecutive naturals, for example, 31944 + ... + 48070.

It is an arithmetic number, because the mean of its divisors is an integer number (88010496).

Almost surely, 2^645192889 is an apocalyptic number.

It is an amenable number.

645192889 is a deficient number, since it is larger than the sum of its proper divisors (58891079).

645192889 is a wasteful number, since it uses less digits than its factorization.

645192889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19775.

The product of its digits is 1244160, while the sum is 52.

The square root of 645192889 is about 25400.6474130090. The cubic root of 645192889 is about 864.0983795905.

The spelling of 645192889 in words is "six hundred forty-five million, one hundred ninety-two thousand, eight hundred eighty-nine".