51481821 has 16 divisors (see below), whose sum is σ = 69905088. Its totient is φ = 33696000.

The previous prime is 51481753. The next prime is 51481823. The reversal of 51481821 is 12818415.

It is a happy number.

51481821 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 51481821 - 2¹⁰ = 51480797 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51481823) 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 15 ways as a sum of consecutive naturals, for example, 39045 + ... + 40341.

It is an arithmetic number, because the mean of its divisors is an integer number (4369068).

Almost surely, 2^51481821 is an apocalyptic number.

It is an amenable number.

51481821 is a deficient number, since it is larger than the sum of its proper divisors (18423267).

51481821 is a wasteful number, since it uses less digits than its factorization.

51481821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1532.

The product of its digits is 2560, while the sum is 30.

The square root of 51481821 is about 7175.0833444637. The cubic root of 51481821 is about 372.0071610947.

The spelling of 51481821 in words is "fifty-one million, four hundred eighty-one thousand, eight hundred twenty-one".