51403581 has 6 divisors (see below), whose sum is σ = 74249630. Its totient is φ = 34269048.

The previous prime is 51403567. The next prime is 51403591. The reversal of 51403581 is 18530415.

51403581 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 34928100 + 16475481 = 5910^2 + 4059^2 .

It is not a de Polignac number, because 51403581 - 2⁷ = 51403453 is a prime.

It is a super-2 number, since 2×51403581² = 5284656279247122, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51403511) 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 5 ways as a sum of consecutive naturals, for example, 2855746 + ... + 2855763.

Almost surely, 2^51403581 is an apocalyptic number.

It is an amenable number.

51403581 is a deficient number, since it is larger than the sum of its proper divisors (22846049).

51403581 is a wasteful number, since it uses less digits than its factorization.

51403581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5711515 (or 5711512 counting only the distinct ones).

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

The square root of 51403581 is about 7169.6290699031. The cubic root of 51403581 is about 371.8186117077.

Adding to 51403581 its reverse (18530415), we get a palindrome (69933996).

It can be divided in two parts, 51403 and 581, that added together give a square (51984 = 228²).

The spelling of 51403581 in words is "fifty-one million, four hundred three thousand, five hundred eighty-one".