51520071506 has 4 divisors (see below), whose sum is σ = 77280107262. Its totient is φ = 25760035752.

The previous prime is 51520071467. The next prime is 51520071523. The reversal of 51520071506 is 60517002515.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 60517002515 = 5 ⋅12103400503.

It can be written as a sum of positive squares in only one way, i.e., 27124443025 + 24395628481 = 164695^2 + 156191^2 .

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12880017875 + ... + 12880017878.

Almost surely, 2^51520071506 is an apocalyptic number.

51520071506 is a deficient number, since it is larger than the sum of its proper divisors (25760035756).

51520071506 is a wasteful number, since it uses less digits than its factorization.

51520071506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25760035755.

The product of its (nonzero) digits is 10500, while the sum is 32.

The spelling of 51520071506 in words is "fifty-one billion, five hundred twenty million, seventy-one thousand, five hundred six".