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72521 = 471543
BaseRepresentation
bin10001101101001001
310200110222
4101231021
54310041
61315425
7421301
oct215511
9120428
1072521
114a539
1235b75
1327017
141c601
151674b
hex11b49

72521 has 4 divisors (see below), whose sum is σ = 74112. Its totient is φ = 70932.

The previous prime is 72503. The next prime is 72533. The reversal of 72521 is 12527.

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 a de Polignac number, because none of the positive numbers 2k-72521 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 72521.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 72521.

It is not an unprimeable number, because it can be changed into a prime (72551) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 725 + ... + 818.

It is an arithmetic number, because the mean of its divisors is an integer number (18528).

272521 is an apocalyptic number.

It is an amenable number.

72521 is a deficient number, since it is larger than the sum of its proper divisors (1591).

72521 is a wasteful number, since it uses less digits than its factorization.

72521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1590.

The product of its digits is 140, while the sum is 17.

The square root of 72521 is about 269.2972335543. The cubic root of 72521 is about 41.7017801785.

It can be divided in two parts, 725 and 21, that multiplied together give a triangular number (15225 = T174).

The spelling of 72521 in words is "seventy-two thousand, five hundred twenty-one".

Divisors: 1 47 1543 72521