51270991 has 2 divisors, whose sum is σ = 51270992. Its totient is φ = 51270990.

The previous prime is 51270983. The next prime is 51271021. The reversal of 51270991 is 19907215.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 51270991 - 2³ = 51270983 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51270971) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25635495 + 25635496.

It is an arithmetic number, because the mean of its divisors is an integer number (25635496).

Almost surely, 2^51270991 is an apocalyptic number.

51270991 is a deficient number, since it is larger than the sum of its proper divisors (1).

51270991 is an equidigital number, since it uses as much as digits as its factorization.

51270991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5670, while the sum is 34.

The square root of 51270991 is about 7160.3764565838. The cubic root of 51270991 is about 371.4986477600.

The spelling of 51270991 in words is "fifty-one million, two hundred seventy thousand, nine hundred ninety-one".