51998521 has 3 divisors (see below), whose sum is σ = 52005733. Its totient is φ = 51991310.

The previous prime is 51998477. The next prime is 51998533. The reversal of 51998521 is 12589915.

The square root of 51998521 is 7211.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a de Polignac number, because none of the positive numbers 2^k-51998521 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51998581) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 3606 + ... + 10816.

Almost surely, 2^51998521 is an apocalyptic number.

51998521 is the 7211-st square number.

51998521 is the 3606-th centered octagonal number.

It is an amenable number.

51998521 is a deficient number, since it is larger than the sum of its proper divisors (7212).

51998521 is an frugal number, since it uses more digits than its factorization.

51998521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14422 (or 7211 counting only the distinct ones).

The product of its digits is 32400, while the sum is 40.

The cubic root of 51998521 is about 373.2475769405.

Multiplying 51998521 by its product of digits (32400), we get a square (1684752080400 = 1297980²).

The spelling of 51998521 in words is "fifty-one million, nine hundred ninety-eight thousand, five hundred twenty-one".