51525981 has 12 divisors (see below), whose sum is σ = 80151708. Its totient is φ = 31708224.

The previous prime is 51525979. The next prime is 51525983. The reversal of 51525981 is 18952515.

It is a happy number.

51525981 is a `hidden beast` number, since 51 + 525 + 9 + 81 = 666.

51525981 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (51525979) and next prime (51525983).

It can be written as a sum of positive squares in 2 ways, for example, as 4040100 + 47485881 = 2010^2 + 6891^2 .

It is not a de Polignac number, because 51525981 - 2¹ = 51525979 is a prime.

It is a super-2 number, since 2×51525981² = 5309853436024722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51525983) 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, 220080 + ... + 220313.

It is an arithmetic number, because the mean of its divisors is an integer number (6679309).

Almost surely, 2^51525981 is an apocalyptic number.

It is an amenable number.

51525981 is a deficient number, since it is larger than the sum of its proper divisors (28625727).

51525981 is a wasteful number, since it uses less digits than its factorization.

51525981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 440412 (or 440409 counting only the distinct ones).

The product of its digits is 18000, while the sum is 36.

The square root of 51525981 is about 7178.1600010030. The cubic root of 51525981 is about 372.1134972796.

The spelling of 51525981 in words is "fifty-one million, five hundred twenty-five thousand, nine hundred eighty-one".