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31439780 = 2251571989
BaseRepresentation
bin111011111101…
…1101110100100
32012011022021022
41313323232210
531022033110
63041510312
7531143111
oct167735644
965138238
1031439780
1116824199
12a642398
13668a428
144265908
152b60755
hex1dfbba4

31439780 has 12 divisors (see below), whose sum is σ = 66023580. Its totient is φ = 12575904.

The previous prime is 31439773. The next prime is 31439791. The reversal of 31439780 is 8793413.

It can be written as a sum of positive squares in 2 ways, for example, as 10719076 + 20720704 = 3274^2 + 4552^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 31439780.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 785975 + ... + 786014.

It is an arithmetic number, because the mean of its divisors is an integer number (5501965).

Almost surely, 231439780 is an apocalyptic number.

It is an amenable number.

31439780 is an abundant number, since it is smaller than the sum of its proper divisors (34583800).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

31439780 is a wasteful number, since it uses less digits than its factorization.

31439780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1571998 (or 1571996 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 35.

The square root of 31439780 is about 5607.1186896658. The cubic root of 31439780 is about 315.6165969073.

The spelling of 31439780 in words is "thirty-one million, four hundred thirty-nine thousand, seven hundred eighty".

Divisors: 1 2 4 5 10 20 1571989 3143978 6287956 7859945 15719890 31439780