645098 has 4 divisors (see below), whose sum is σ = 967650. Its totient is φ = 322548.

The previous prime is 645097. The next prime is 645131. The reversal of 645098 is 890546.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 644809 + 289 = 803^2 + 17^2 .

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 645098.

It is not an unprimeable number, because it can be changed into a prime (645091) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 161273 + ... + 161276.

2⁶⁴⁵⁰⁹⁸ is an apocalyptic number.

645098 is a deficient number, since it is larger than the sum of its proper divisors (322552).

645098 is a wasteful number, since it uses less digits than its factorization.

645098 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 322551.

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

The square root of 645098 is about 803.1799300281. The cubic root of 645098 is about 86.4056016316.

The spelling of 645098 in words is "six hundred forty-five thousand, ninety-eight".