51645019 has 2 divisors, whose sum is σ = 51645020. Its totient is φ = 51645018.

The previous prime is 51644987. The next prime is 51645023. The reversal of 51645019 is 91054615.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 51645019 - 2⁵ = 51644987 is a prime.

It is a super-2 number, since 2×51645019² = 5334415975020722, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (51645029) 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, 25822509 + 25822510.

It is an arithmetic number, because the mean of its divisors is an integer number (25822510).

Almost surely, 2^51645019 is an apocalyptic number.

51645019 is a deficient number, since it is larger than the sum of its proper divisors (1).

51645019 is an equidigital number, since it uses as much as digits as its factorization.

51645019 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5400, while the sum is 31.

The square root of 51645019 is about 7186.4468967634. The cubic root of 51645019 is about 372.3998355371.

The spelling of 51645019 in words is "fifty-one million, six hundred forty-five thousand, nineteen".