51661005 has 32 divisors (see below), whose sum is σ = 91428480. Its totient is φ = 24698880.

The previous prime is 51661003. The next prime is 51661063. The reversal of 51661005 is 50016615.

It is not a de Polignac number, because 51661005 - 2¹ = 51661003 is a prime.

It is a super-2 number, since 2×51661005² = 5337718875220050, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51661003) 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 31 ways as a sum of consecutive naturals, for example, 9901 + ... + 14189.

It is an arithmetic number, because the mean of its divisors is an integer number (2857140).

Almost surely, 2^51661005 is an apocalyptic number.

51661005 is a gapful number since it is divisible by the number (55) formed by its first and last digit.

It is an amenable number.

51661005 is a deficient number, since it is larger than the sum of its proper divisors (39767475).

51661005 is a wasteful number, since it uses less digits than its factorization.

51661005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4381.

The product of its (nonzero) digits is 900, while the sum is 24.

The square root of 51661005 is about 7187.5590432357. The cubic root of 51661005 is about 372.4382553095.

The spelling of 51661005 in words is "fifty-one million, six hundred sixty-one thousand, five".