51031521 has 12 divisors (see below), whose sum is σ = 74294272. Its totient is φ = 33752376.

The previous prime is 51031499. The next prime is 51031523. The reversal of 51031521 is 12513015.

51031521 is a `hidden beast` number, since 510 + 3 + 152 + 1 = 666.

51031521 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 51031521 - 2⁵ = 51031489 is a prime.

It is a super-2 number, since 2×51031521² = 5208432271146882, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 51031494 and 51031503.

It is not an unprimeable number, because it can be changed into a prime (51031523) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 21181 + ... + 23466.

Almost surely, 2^51031521 is an apocalyptic number.

It is an amenable number.

51031521 is a deficient number, since it is larger than the sum of its proper divisors (23262751).

51031521 is a wasteful number, since it uses less digits than its factorization.

51031521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44780 (or 44777 counting only the distinct ones).

The product of its (nonzero) digits is 150, while the sum is 18.

The square root of 51031521 is about 7143.6349990744. The cubic root of 51031521 is about 370.9193621166.

Adding to 51031521 its reverse (12513015), we get a palindrome (63544536).

The spelling of 51031521 in words is "fifty-one million, thirty-one thousand, five hundred twenty-one".