51111651505 has 8 divisors (see below), whose sum is σ = 61337973672. Its totient is φ = 40886659968.

The previous prime is 51111651449. The next prime is 51111651511. The reversal of 51111651505 is 50515611115.

It can be written as a sum of positive squares in 4 ways, for example, as 27039198096 + 24072453409 = 164436^2 + 155153^2 .

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 51111651505 - 2¹³ = 51111643313 is a prime.

It is a super-2 number, since 2×51111651505² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 246102 + ... + 403471.

It is an arithmetic number, because the mean of its divisors is an integer number (7667246709).

Almost surely, 2^51111651505 is an apocalyptic number.

It is an amenable number.

51111651505 is a deficient number, since it is larger than the sum of its proper divisors (10226322167).

51111651505 is a wasteful number, since it uses less digits than its factorization.

51111651505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 665315.

The product of its (nonzero) digits is 3750, while the sum is 31.

The spelling of 51111651505 in words is "fifty-one billion, one hundred eleven million, six hundred fifty-one thousand, five hundred five".