51644881 has 2 divisors, whose sum is σ = 51644882. Its totient is φ = 51644880.

The previous prime is 51644863. The next prime is 51644891. The reversal of 51644881 is 18844615.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 33454656 + 18190225 = 5784^2 + 4265^2 .

It is a cyclic number.

It is not a de Polignac number, because 51644881 - 2¹⁷ = 51513809 is a prime.

It is a super-2 number, since 2×51644881² = 5334387467008322, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 51644881.

It is not a weakly prime, because it can be changed into another prime (51644851) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25822440 + 25822441.

It is an arithmetic number, because the mean of its divisors is an integer number (25822441).

Almost surely, 2^51644881 is an apocalyptic number.

It is an amenable number.

51644881 is a deficient number, since it is larger than the sum of its proper divisors (1).

51644881 is an equidigital number, since it uses as much as digits as its factorization.

51644881 is an evil number, because the sum of its binary digits is even.

The product of its digits is 30720, while the sum is 37.

The square root of 51644881 is about 7186.4372953502. The cubic root of 51644881 is about 372.3995038418.

It can be divided in two parts, 51644 and 881, that added together give a palindrome (52525).

The spelling of 51644881 in words is "fifty-one million, six hundred forty-four thousand, eight hundred eighty-one".