51720313 has 2 divisors, whose sum is σ = 51720314. Its totient is φ = 51720312.

The previous prime is 51720301. The next prime is 51720323. The reversal of 51720313 is 31302715.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 33674809 + 18045504 = 5803^2 + 4248^2 .

It is a cyclic number.

It is not a de Polignac number, because 51720313 - 2¹³ = 51712121 is a prime.

It is not a weakly prime, because it can be changed into another prime (51720323) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25860156 + 25860157.

It is an arithmetic number, because the mean of its divisors is an integer number (25860157).

Almost surely, 2^51720313 is an apocalyptic number.

It is an amenable number.

51720313 is a deficient number, since it is larger than the sum of its proper divisors (1).

51720313 is an equidigital number, since it uses as much as digits as its factorization.

51720313 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 630, while the sum is 22.

The square root of 51720313 is about 7191.6835998256. The cubic root of 51720313 is about 372.5807233129.

The spelling of 51720313 in words is "fifty-one million, seven hundred twenty thousand, three hundred thirteen".