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640436 = 22295521
BaseRepresentation
bin10011100010110110100
31012112111212
42130112310
5130443221
621420552
75305106
oct2342664
91175455
10640436
113a8195
1226a758
13195674
14129576
15c9b5b
hex9c5b4

640436 has 12 divisors (see below), whose sum is σ = 1159620. Its totient is φ = 309120.

The previous prime is 640421. The next prime is 640457. The reversal of 640436 is 634046.

640436 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 256036 + 384400 = 506^2 + 620^2 .

It is a congruent number.

It is an unprimeable number.

640436 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2645 + ... + 2876.

It is an arithmetic number, because the mean of its divisors is an integer number (96635).

2640436 is an apocalyptic number.

It is an amenable number.

640436 is a deficient number, since it is larger than the sum of its proper divisors (519184).

640436 is a wasteful number, since it uses less digits than its factorization.

640436 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5554 (or 5552 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 23.

The square root of 640436 is about 800.2724536056. The cubic root of 640436 is about 86.1969526075.

The spelling of 640436 in words is "six hundred forty thousand, four hundred thirty-six".

Divisors: 1 2 4 29 58 116 5521 11042 22084 160109 320218 640436