51111665 has 8 divisors (see below), whose sum is σ = 66909888. Its totient is φ = 37172080.

The previous prime is 51111661. The next prime is 51111677. The reversal of 51111665 is 56611115.

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

It is not a de Polignac number, because 51111665 - 2² = 51111661 is a prime.

It is a super-2 number, since 2×51111665² = 5224804598144450, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51111661) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 464597 + ... + 464706.

It is an arithmetic number, because the mean of its divisors is an integer number (8363736).

Almost surely, 2^51111665 is an apocalyptic number.

51111665 is a gapful number since it is divisible by the number (55) formed by its first and last digit.

It is an amenable number.

51111665 is a deficient number, since it is larger than the sum of its proper divisors (15798223).

51111665 is a wasteful number, since it uses less digits than its factorization.

51111665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 929319.

The product of its digits is 900, while the sum is 26.

The square root of 51111665 is about 7149.2422675414. The cubic root of 51111665 is about 371.1134344107.

It can be divided in two parts, 5111 and 1665, that added together give a palindrome (6776).

The spelling of 51111665 in words is "fifty-one million, one hundred eleven thousand, six hundred sixty-five".