645454 has 4 divisors (see below), whose sum is σ = 968184. Its totient is φ = 322726.

The previous prime is 645443. The next prime is 645467. The reversal of 645454 is 454546.

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

It is a super-2 number, since 2×645454² = 833221732232, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 161362 + ... + 161365.

It is an arithmetic number, because the mean of its divisors is an integer number (242046).

2⁶⁴⁵⁴⁵⁴ is an apocalyptic number.

645454 is a deficient number, since it is larger than the sum of its proper divisors (322730).

645454 is a wasteful number, since it uses less digits than its factorization.

645454 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 322729.

The product of its digits is 9600, while the sum is 28.

The square root of 645454 is about 803.4015185447. The cubic root of 645454 is about 86.4214931382.

The spelling of 645454 in words is "six hundred forty-five thousand, four hundred fifty-four".