51720673 has 2 divisors, whose sum is σ = 51720674. Its totient is φ = 51720672.

The previous prime is 51720637. The next prime is 51720677. The reversal of 51720673 is 37602715.

Together with previous prime (51720637) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 45535504 + 6185169 = 6748^2 + 2487^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51720673 is a prime.

It is not a weakly prime, because it can be changed into another prime (51720677) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25860336 + 25860337.

It is an arithmetic number, because the mean of its divisors is an integer number (25860337).

Almost surely, 2^51720673 is an apocalyptic number.

It is an amenable number.

51720673 is a deficient number, since it is larger than the sum of its proper divisors (1).

51720673 is an equidigital number, since it uses as much as digits as its factorization.

51720673 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8820, while the sum is 31.

The square root of 51720673 is about 7191.7086286918. The cubic root of 51720673 is about 372.5815877621.

The spelling of 51720673 in words is "fifty-one million, seven hundred twenty thousand, six hundred seventy-three".