51720521073 has 16 divisors (see below), whose sum is σ = 74710075776. Its totient is φ = 31637422080.

The previous prime is 51720521033. The next prime is 51720521113. The reversal of 51720521073 is 37012502715.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (51720521033) and next prime (51720521113).

It is not a de Polignac number, because 51720521073 - 2⁹ = 51720520561 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (51720521033) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3964048 + ... + 3977073.

It is an arithmetic number, because the mean of its divisors is an integer number (4669379736).

Almost surely, 2^51720521073 is an apocalyptic number.

It is an amenable number.

51720521073 is a deficient number, since it is larger than the sum of its proper divisors (22989554703).

51720521073 is a wasteful number, since it uses less digits than its factorization.

51720521073 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7941304.

The product of its (nonzero) digits is 14700, while the sum is 33.

The spelling of 51720521073 in words is "fifty-one billion, seven hundred twenty million, five hundred twenty-one thousand, seventy-three".