51804989 has 2 divisors, whose sum is σ = 51804990. Its totient is φ = 51804988.

The previous prime is 51804971. The next prime is 51804997. The reversal of 51804989 is 98940815.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 47844889 + 3960100 = 6917^2 + 1990^2 .

It is a cyclic number.

It is not a de Polignac number, because 51804989 - 2⁸ = 51804733 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51804959) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25902494 + 25902495.

It is an arithmetic number, because the mean of its divisors is an integer number (25902495).

Almost surely, 2^51804989 is an apocalyptic number.

It is an amenable number.

51804989 is a deficient number, since it is larger than the sum of its proper divisors (1).

51804989 is an equidigital number, since it uses as much as digits as its factorization.

51804989 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 103680, while the sum is 44.

The square root of 51804989 is about 7197.5682699089. The cubic root of 51804989 is about 372.7839409792.

The spelling of 51804989 in words is "fifty-one million, eight hundred four thousand, nine hundred eighty-nine".