51661216 has 12 divisors (see below), whose sum is σ = 101708082. Its totient is φ = 25830592.

The previous prime is 51661153. The next prime is 51661219. The reversal of 51661216 is 61216615.

It can be written as a sum of positive squares in only one way, i.e., 46185616 + 5475600 = 6796^2 + 2340^2 .

It is not an unprimeable number, because it can be changed into a prime (51661219) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 807175 + ... + 807238.

Almost surely, 2^51661216 is an apocalyptic number.

It is an amenable number.

51661216 is a deficient number, since it is larger than the sum of its proper divisors (50046866).

51661216 is a wasteful number, since it uses less digits than its factorization.

51661216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1614423 (or 1614415 counting only the distinct ones).

The product of its digits is 2160, while the sum is 28.

The square root of 51661216 is about 7187.5737213611. The cubic root of 51661216 is about 372.4387623610.

The spelling of 51661216 in words is "fifty-one million, six hundred sixty-one thousand, two hundred sixteen".