645089 has 4 divisors (see below), whose sum is σ = 651456. Its totient is φ = 638724.

The previous prime is 645083. The next prime is 645091. The reversal of 645089 is 980546.

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 645089 - 2¹² = 640993 is a prime.

It is a super-2 number, since 2×645089² = 832279635842, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (645083) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3029 + ... + 3234.

It is an arithmetic number, because the mean of its divisors is an integer number (162864).

2⁶⁴⁵⁰⁸⁹ is an apocalyptic number.

It is an amenable number.

645089 is a deficient number, since it is larger than the sum of its proper divisors (6367).

645089 is a wasteful number, since it uses less digits than its factorization.

645089 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6366.

The product of its (nonzero) digits is 8640, while the sum is 32.

The square root of 645089 is about 803.1743272790. The cubic root of 645089 is about 86.4051998042.

The spelling of 645089 in words is "six hundred forty-five thousand, eighty-nine".