51989557 has 2 divisors, whose sum is σ = 51989558. Its totient is φ = 51989556.

The previous prime is 51989549. The next prime is 51989563. The reversal of 51989557 is 75598915.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 42693156 + 9296401 = 6534^2 + 3049^2 .

It is a cyclic number.

It is not a de Polignac number, because 51989557 - 2³ = 51989549 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 51989557.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51989657) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25994778 + 25994779.

It is an arithmetic number, because the mean of its divisors is an integer number (25994779).

Almost surely, 2^51989557 is an apocalyptic number.

It is an amenable number.

51989557 is a deficient number, since it is larger than the sum of its proper divisors (1).

51989557 is an equidigital number, since it uses as much as digits as its factorization.

51989557 is an evil number, because the sum of its binary digits is even.

The product of its digits is 567000, while the sum is 49.

The square root of 51989557 is about 7210.3784228014. The cubic root of 51989557 is about 373.2261277179.

The spelling of 51989557 in words is "fifty-one million, nine hundred eighty-nine thousand, five hundred fifty-seven".