51987641 has 2 divisors, whose sum is σ = 51987642. Its totient is φ = 51987640.

The previous prime is 51987623. The next prime is 51987643. The reversal of 51987641 is 14678915.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 41229241 + 10758400 = 6421^2 + 3280^2 .

It is a cyclic number.

It is not a de Polignac number, because 51987641 - 2¹⁰ = 51986617 is a prime.

It is a Sophie Germain prime.

Together with 51987643, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (51987643) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25993820 + 25993821.

It is an arithmetic number, because the mean of its divisors is an integer number (25993821).

Almost surely, 2^51987641 is an apocalyptic number.

It is an amenable number.

51987641 is a deficient number, since it is larger than the sum of its proper divisors (1).

51987641 is an equidigital number, since it uses as much as digits as its factorization.

51987641 is an evil number, because the sum of its binary digits is even.

The product of its digits is 60480, while the sum is 41.

The square root of 51987641 is about 7210.2455575382. The cubic root of 51987641 is about 373.2215427583.

The spelling of 51987641 in words is "fifty-one million, nine hundred eighty-seven thousand, six hundred forty-one".