51213825 has 36 divisors (see below), whose sum is σ = 98791420. Its totient is φ = 25211520.

The previous prime is 51213823. The next prime is 51213857. The reversal of 51213825 is 52831215.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 20875761 + 30338064 = 4569^2 + 5508^2 .

It is not a de Polignac number, because 51213825 - 2¹ = 51213823 is a prime.

It is a super-2 number, since 2×51213825² = 5245711742261250, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (51213821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 5830 + ... + 11679.

Almost surely, 2^51213825 is an apocalyptic number.

It is an amenable number.

51213825 is a deficient number, since it is larger than the sum of its proper divisors (47577595).

51213825 is a wasteful number, since it uses less digits than its factorization.

51213825 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17538 (or 17530 counting only the distinct ones).

The product of its digits is 2400, while the sum is 27.

The square root of 51213825 is about 7156.3835140384. The cubic root of 51213825 is about 371.3605255384.

The spelling of 51213825 in words is "fifty-one million, two hundred thirteen thousand, eight hundred twenty-five".