51039481 has 2 divisors, whose sum is σ = 51039482. Its totient is φ = 51039480.

The previous prime is 51039479. The next prime is 51039517. The reversal of 51039481 is 18493015.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 49829481 + 1210000 = 7059^2 + 1100^2 .

It is a cyclic number.

It is not a de Polignac number, because 51039481 - 2¹ = 51039479 is a prime.

It is a super-2 number, since 2×51039481² = 5210057241498722, which contains 22 as substring.

Together with 51039479, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (51039181) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25519740 + 25519741.

It is an arithmetic number, because the mean of its divisors is an integer number (25519741).

Almost surely, 2^51039481 is an apocalyptic number.

It is an amenable number.

51039481 is a deficient number, since it is larger than the sum of its proper divisors (1).

51039481 is an equidigital number, since it uses as much as digits as its factorization.

51039481 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4320, while the sum is 31.

The square root of 51039481 is about 7144.1921166777. The cubic root of 51039481 is about 370.9386466984.

The spelling of 51039481 in words is "fifty-one million, thirty-nine thousand, four hundred eighty-one".