18616521 has 48 divisors (see below), whose sum is σ = 32667840. Its totient is φ = 9313920.

The previous prime is 18616517. The next prime is 18616567. The reversal of 18616521 is 12561681.

It is not a de Polignac number, because 18616521 - 2² = 18616517 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18616511) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 46695 + ... + 47091.

It is an arithmetic number, because the mean of its divisors is an integer number (680580).

Almost surely, 2^18616521 is an apocalyptic number.

18616521 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

18616521 is a deficient number, since it is larger than the sum of its proper divisors (14051319).

18616521 is a wasteful number, since it uses less digits than its factorization.

18616521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 454 (or 447 counting only the distinct ones).

The product of its digits is 2880, while the sum is 30.

The square root of 18616521 is about 4314.6866630151. The cubic root of 18616521 is about 265.0327288401.

The spelling of 18616521 in words is "eighteen million, six hundred sixteen thousand, five hundred twenty-one".