51720323 has 2 divisors, whose sum is σ = 51720324. Its totient is φ = 51720322.

The previous prime is 51720313. The next prime is 51720329. The reversal of 51720323 is 32302715.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51720323 is a prime.

It is a super-2 number, since 2×51720323² = 5349983622448658, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (51720329) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25860161 + 25860162.

It is an arithmetic number, because the mean of its divisors is an integer number (25860162).

Almost surely, 2^51720323 is an apocalyptic number.

51720323 is a deficient number, since it is larger than the sum of its proper divisors (1).

51720323 is an equidigital number, since it uses as much as digits as its factorization.

51720323 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1260, while the sum is 23.

The square root of 51720323 is about 7191.6842950730. The cubic root of 51720323 is about 372.5807473254.

The spelling of 51720323 in words is "fifty-one million, seven hundred twenty thousand, three hundred twenty-three".