51818521 has 2 divisors, whose sum is σ = 51818522. Its totient is φ = 51818520.

The previous prime is 51818513. The next prime is 51818561. The reversal of 51818521 is 12581815.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 38937600 + 12880921 = 6240^2 + 3589^2 .

It is a cyclic number.

It is not a de Polignac number, because 51818521 - 2³ = 51818513 is a prime.

It is not a weakly prime, because it can be changed into another prime (51818561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25909260 + 25909261.

It is an arithmetic number, because the mean of its divisors is an integer number (25909261).

Almost surely, 2^51818521 is an apocalyptic number.

It is an amenable number.

51818521 is a deficient number, since it is larger than the sum of its proper divisors (1).

51818521 is an equidigital number, since it uses as much as digits as its factorization.

51818521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3200, while the sum is 31.

The square root of 51818521 is about 7198.5082482414. The cubic root of 51818521 is about 372.8163964964.

The spelling of 51818521 in words is "fifty-one million, eight hundred eighteen thousand, five hundred twenty-one".