51661017 has 16 divisors (see below), whose sum is σ = 78316480. Its totient is φ = 33638976.

The previous prime is 51661003. The next prime is 51661063. The reversal of 51661017 is 71016615.

It is a de Polignac number, because none of the positive numbers 2^k-51661017 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51661067) 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 15 ways as a sum of consecutive naturals, for example, 21088 + ... + 23409.

It is an arithmetic number, because the mean of its divisors is an integer number (4894780).

Almost surely, 2^51661017 is an apocalyptic number.

It is an amenable number.

51661017 is a deficient number, since it is larger than the sum of its proper divisors (26655463).

51661017 is a wasteful number, since it uses less digits than its factorization.

51661017 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44549 (or 44543 counting only the distinct ones).

The product of its (nonzero) digits is 1260, while the sum is 27.

The square root of 51661017 is about 7187.5598780115. The cubic root of 51661017 is about 372.4382841466.

The spelling of 51661017 in words is "fifty-one million, six hundred sixty-one thousand, seventeen".