51017639 has 2 divisors, whose sum is σ = 51017640. Its totient is φ = 51017638.

The previous prime is 51017627. The next prime is 51017677. The reversal of 51017639 is 93671015.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 51017639 - 2⁴ = 51017623 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51017539) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25508819 + 25508820.

It is an arithmetic number, because the mean of its divisors is an integer number (25508820).

Almost surely, 2^51017639 is an apocalyptic number.

51017639 is a deficient number, since it is larger than the sum of its proper divisors (1).

51017639 is an equidigital number, since it uses as much as digits as its factorization.

51017639 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5670, while the sum is 32.

The square root of 51017639 is about 7142.6632987983. The cubic root of 51017639 is about 370.8857255886.

The spelling of 51017639 in words is "fifty-one million, seventeen thousand, six hundred thirty-nine".