51986581 has 2 divisors, whose sum is σ = 51986582. Its totient is φ = 51986580.

The previous prime is 51986537. The next prime is 51986609. The reversal of 51986581 is 18568915.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 51969681 + 16900 = 7209^2 + 130^2 .

It is a cyclic number.

It is not a de Polignac number, because 51986581 - 2⁷ = 51986453 is a prime.

It is a super-2 number, since 2×51986581² = 5405209208139122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51986521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25993290 + 25993291.

It is an arithmetic number, because the mean of its divisors is an integer number (25993291).

Almost surely, 2^51986581 is an apocalyptic number.

It is an amenable number.

51986581 is a deficient number, since it is larger than the sum of its proper divisors (1).

51986581 is an equidigital number, since it uses as much as digits as its factorization.

51986581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 86400, while the sum is 43.

The square root of 51986581 is about 7210.1720506518. The cubic root of 51986581 is about 373.2190061457.

The spelling of 51986581 in words is "fifty-one million, nine hundred eighty-six thousand, five hundred eighty-one".