51520071561 has 16 divisors (see below), whose sum is σ = 78525527424. Its totient is φ = 29433009024.

The previous prime is 51520071541. The next prime is 51520071569. The reversal of 51520071561 is 16517002515.

It is a happy number.

It is not a de Polignac number, because 51520071561 - 2⁵ = 51520071529 is a prime.

It is a super-3 number, since 3×51520071561³ (a number of 33 digits) contains 333 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (51520071569) 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, 202330 + ... + 379443.

It is an arithmetic number, because the mean of its divisors is an integer number (4907845464).

Almost surely, 2^51520071561 is an apocalyptic number.

It is an amenable number.

51520071561 is a deficient number, since it is larger than the sum of its proper divisors (27005455863).

51520071561 is a wasteful number, since it uses less digits than its factorization.

51520071561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 586000.

The product of its (nonzero) digits is 10500, while the sum is 33.

The spelling of 51520071561 in words is "fifty-one billion, five hundred twenty million, seventy-one thousand, five hundred sixty-one".