51663791 has 2 divisors, whose sum is σ = 51663792. Its totient is φ = 51663790.

The previous prime is 51663751. The next prime is 51663847. The reversal of 51663791 is 19736615.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51663791 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51663751) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25831895 + 25831896.

It is an arithmetic number, because the mean of its divisors is an integer number (25831896).

Almost surely, 2^51663791 is an apocalyptic number.

51663791 is a deficient number, since it is larger than the sum of its proper divisors (1).

51663791 is an equidigital number, since it uses as much as digits as its factorization.

51663791 is an evil number, because the sum of its binary digits is even.

The product of its digits is 34020, while the sum is 38.

The square root of 51663791 is about 7187.7528477265. The cubic root of 51663791 is about 372.4449502001. Note that the first 3 decimals are identical.

The spelling of 51663791 in words is "fifty-one million, six hundred sixty-three thousand, seven hundred ninety-one".