51986381 has 2 divisors, whose sum is σ = 51986382. Its totient is φ = 51986380.

The previous prime is 51986377. The next prime is 51986383. The reversal of 51986381 is 18368915.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 27730756 + 24255625 = 5266^2 + 4925^2 .

It is a cyclic number.

It is not a de Polignac number, because 51986381 - 2² = 51986377 is a prime.

It is a super-3 number, since 3×51986381³ (a number of 24 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

Together with 51986383, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51986383) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25993190 + 25993191.

It is an arithmetic number, because the mean of its divisors is an integer number (25993191).

Almost surely, 2^51986381 is an apocalyptic number.

It is an amenable number.

51986381 is a deficient number, since it is larger than the sum of its proper divisors (1).

51986381 is an equidigital number, since it uses as much as digits as its factorization.

51986381 is an evil number, because the sum of its binary digits is even.

The product of its digits is 51840, while the sum is 41.

The square root of 51986381 is about 7210.1581813439. The cubic root of 51986381 is about 373.2185275356.

The spelling of 51986381 in words is "fifty-one million, nine hundred eighty-six thousand, three hundred eighty-one".