51806661 has 8 divisors (see below), whose sum is σ = 70246560. Its totient is φ = 33952272.

The previous prime is 51806659. The next prime is 51806663. The reversal of 51806661 is 16660815.

It is an interprime number because it is at equal distance from previous prime (51806659) and next prime (51806663).

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

It is not a de Polignac number, because 51806661 - 2¹ = 51806659 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51806663) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 146170 + ... + 146523.

It is an arithmetic number, because the mean of its divisors is an integer number (8780820).

Almost surely, 2^51806661 is an apocalyptic number.

It is an amenable number.

51806661 is a deficient number, since it is larger than the sum of its proper divisors (18439899).

51806661 is a wasteful number, since it uses less digits than its factorization.

51806661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 292755.

The product of its (nonzero) digits is 8640, while the sum is 33.

The square root of 51806661 is about 7197.6844193115. The cubic root of 51806661 is about 372.7879514555.

The spelling of 51806661 in words is "fifty-one million, eight hundred six thousand, six hundred sixty-one".