646973 has 4 divisors (see below), whose sum is σ = 649920. Its totient is φ = 644028.

The previous prime is 646957. The next prime is 646979. The reversal of 646973 is 379646.

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, and also an emirpimes, since its reverse is a distinct semiprime: 379646 = 2 ⋅189823.

It is a cyclic number.

It is not a de Polignac number, because 646973 - 2⁴ = 646957 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 646973.

It is not an unprimeable number, because it can be changed into a prime (646979) 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, 1115 + ... + 1592.

It is an arithmetic number, because the mean of its divisors is an integer number (162480).

2⁶⁴⁶⁹⁷³ is an apocalyptic number.

It is an amenable number.

646973 is a deficient number, since it is larger than the sum of its proper divisors (2947).

646973 is a wasteful number, since it uses less digits than its factorization.

646973 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2946.

The product of its digits is 27216, while the sum is 35.

The square root of 646973 is about 804.3463184475. The cubic root of 646973 is about 86.4892342956.

The spelling of 646973 in words is "six hundred forty-six thousand, nine hundred seventy-three".