642447 has 36 divisors (see below), whose sum is σ = 1117480. Its totient is φ = 352512.

The previous prime is 642427. The next prime is 642457. The reversal of 642447 is 744246.

It is not a de Polignac number, because 642447 - 2¹⁴ = 626063 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 642447.

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 642447.

It is not an unprimeable number, because it can be changed into a prime (642407) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 33804 + ... + 33822.

2⁶⁴²⁴⁴⁷ is an apocalyptic number.

642447 is a deficient number, since it is larger than the sum of its proper divisors (475033).

642447 is a wasteful number, since it uses less digits than its factorization.

642447 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72 (or 52 counting only the distinct ones).

The product of its digits is 5376, while the sum is 27.

The square root of 642447 is about 801.5279159206. The cubic root of 642447 is about 86.2870792053.

It can be divided in two parts, 642 and 447, that added together give a square (1089 = 33²).

The spelling of 642447 in words is "six hundred forty-two thousand, four hundred forty-seven".