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31530 = 2351051

31530 has 16 divisors (see below), whose sum is σ = 75744. Its totient is φ = 8400.

The previous prime is 31517. The next prime is 31531. The reversal of 31530 is 3513.

It is a happy number.

It is a nialpdrome in base 15.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 31530.

It is not an unprimeable number, because it can be changed into a prime (31531) by changing a digit.

31530 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 7 ways as a sum of consecutive naturals, for example, 496 + ... + 555.

It is an arithmetic number, because the mean of its divisors is an integer number (4734).

231530 is an apocalyptic number.

31530 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

31530 is an abundant number, since it is smaller than the sum of its proper divisors (44214).

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

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37872).

31530 is a wasteful number, since it uses less digits than its factorization.

31530 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1061.

The product of its (nonzero) digits is 45, while the sum is 12.

The square root of 31530 is about 177.5668888053. The cubic root of 31530 is about 31.5918207747.

It can be divided in two parts, 31 and 530, that added together give a triangular number (561 = T33).

The spelling of 31530 in words is "thirty-one thousand, five hundred thirty".

Divisors: 1 2 3 5 6 10 15 30 1051 2102 3153 5255 6306 10510 15765 31530