51078491 has 2 divisors, whose sum is σ = 51078492. Its totient is φ = 51078490.

The previous prime is 51078481. The next prime is 51078509. The reversal of 51078491 is 19487015.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51078491 is a prime.

It is not a weakly prime, because it can be changed into another prime (51078451) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25539245 + 25539246.

It is an arithmetic number, because the mean of its divisors is an integer number (25539246).

Almost surely, 2^51078491 is an apocalyptic number.

51078491 is a deficient number, since it is larger than the sum of its proper divisors (1).

51078491 is an equidigital number, since it uses as much as digits as its factorization.

51078491 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10080, while the sum is 35.

The square root of 51078491 is about 7146.9217849365. The cubic root of 51078491 is about 371.0331267054.

The spelling of 51078491 in words is "fifty-one million, seventy-eight thousand, four hundred ninety-one".