51720311 has 8 divisors (see below), whose sum is σ = 54810000. Its totient is φ = 48717760.

The previous prime is 51720301. The next prime is 51720313. The reversal of 51720311 is 11302715.

51720311 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 51720311 - 2⁶ = 51720247 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51720313) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20561 + ... + 22938.

It is an arithmetic number, because the mean of its divisors is an integer number (6851250).

Almost surely, 2^51720311 is an apocalyptic number.

51720311 is a deficient number, since it is larger than the sum of its proper divisors (3089689).

51720311 is a wasteful number, since it uses less digits than its factorization.

51720311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43569.

The product of its (nonzero) digits is 210, while the sum is 20.

The square root of 51720311 is about 7191.6834607761. The cubic root of 51720311 is about 372.5807185104.

The spelling of 51720311 in words is "fifty-one million, seven hundred twenty thousand, three hundred eleven".