30521 has 4 divisors (see below), whose sum is σ = 31872. Its totient is φ = 29172.

The previous prime is 30517. The next prime is 30529. The reversal of 30521 is 12503.

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 not a de Polignac number, because 30521 - 2² = 30517 is a prime.

It is a super-3 number, since 3×30521³ = 85293813332283, which contains 333 as substring.

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 not an unprimeable number, because it can be changed into a prime (30529) 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, 641 + ... + 686.

It is an arithmetic number, because the mean of its divisors is an integer number (7968).

2³⁰⁵²¹ is an apocalyptic number.

It is an amenable number.

30521 is a deficient number, since it is larger than the sum of its proper divisors (1351).

30521 is a wasteful number, since it uses less digits than its factorization.

30521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1350.

The product of its (nonzero) digits is 30, while the sum is 11.

The square root of 30521 is about 174.7026044454. The cubic root of 30521 is about 31.2511679563.

The spelling of 30521 in words is "thirty thousand, five hundred twenty-one".