51145987 has 2 divisors, whose sum is σ = 51145988. Its totient is φ = 51145986.

The previous prime is 51145957. The next prime is 51145993. The reversal of 51145987 is 78954115.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51145987 is a prime.

It is not a weakly prime, because it can be changed into another prime (51145957) 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, 25572993 + 25572994.

It is an arithmetic number, because the mean of its divisors is an integer number (25572994).

Almost surely, 2^51145987 is an apocalyptic number.

51145987 is a deficient number, since it is larger than the sum of its proper divisors (1).

51145987 is an equidigital number, since it uses as much as digits as its factorization.

51145987 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 50400, while the sum is 40.

The square root of 51145987 is about 7151.6422589500. The cubic root of 51145987 is about 371.1964846320.

The spelling of 51145987 in words is "fifty-one million, one hundred forty-five thousand, nine hundred eighty-seven".