645629889 has 8 divisors (see below), whose sum is σ = 873688480. Its totient is φ = 423995616.

The previous prime is 645629869. The next prime is 645629891. The reversal of 645629889 is 988926546.

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

It is a de Polignac number, because none of the positive numbers 2^k-645629889 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (645629869) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1605844 + ... + 1606245.

It is an arithmetic number, because the mean of its divisors is an integer number (109211060).

Almost surely, 2^645629889 is an apocalyptic number.

It is an amenable number.

645629889 is a deficient number, since it is larger than the sum of its proper divisors (228058591).

645629889 is a wasteful number, since it uses less digits than its factorization.

645629889 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3212159.

The product of its digits is 7464960, while the sum is 57.

The square root of 645629889 is about 25409.2480998553. The cubic root of 645629889 is about 864.2934250186.

The spelling of 645629889 in words is "six hundred forty-five million, six hundred twenty-nine thousand, eight hundred eighty-nine".