Search a number
-
+
642989 = 6311019
BaseRepresentation
bin10011100111110101101
31012200000102
42130332231
5131033424
621440445
75315414
oct2347655
91180012
10642989
113aa0a6
12270125
13196889
1412a47b
15ca7ae
hex9cfad

642989 has 4 divisors (see below), whose sum is σ = 644640. Its totient is φ = 641340.

The previous prime is 642977. The next prime is 642997. The reversal of 642989 is 989246.

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 642989 - 24 = 642973 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42989) 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 in 3 ways as a sum of consecutive naturals, for example, 122 + ... + 1140.

It is an arithmetic number, because the mean of its divisors is an integer number (161160).

2642989 is an apocalyptic number.

It is an amenable number.

642989 is a deficient number, since it is larger than the sum of its proper divisors (1651).

642989 is a wasteful number, since it uses less digits than its factorization.

642989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1650.

The product of its digits is 31104, while the sum is 38.

The square root of 642989 is about 801.8659488967. The cubic root of 642989 is about 86.3113377310.

The spelling of 642989 in words is "six hundred forty-two thousand, nine hundred eighty-nine".

Divisors: 1 631 1019 642989