51218971 has 2 divisors, whose sum is σ = 51218972. Its totient is φ = 51218970.

The previous prime is 51218969. The next prime is 51218983. The reversal of 51218971 is 17981215.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 51218971 - 2¹ = 51218969 is a prime.

Together with 51218969, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (51218911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25609485 + 25609486.

It is an arithmetic number, because the mean of its divisors is an integer number (25609486).

Almost surely, 2^51218971 is an apocalyptic number.

51218971 is a deficient number, since it is larger than the sum of its proper divisors (1).

51218971 is an equidigital number, since it uses as much as digits as its factorization.

51218971 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5040, while the sum is 34.

The square root of 51218971 is about 7156.7430441507. The cubic root of 51218971 is about 371.3729633079.

The spelling of 51218971 in words is "fifty-one million, two hundred eighteen thousand, nine hundred seventy-one".