51555668 has 6 divisors (see below), whose sum is σ = 90222426. Its totient is φ = 25777832.

The previous prime is 51555661. The next prime is 51555671. The reversal of 51555668 is 86655515.

It can be written as a sum of positive squares in only one way, i.e., 30780304 + 20775364 = 5548^2 + 4558^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51555661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6444455 + ... + 6444462.

It is an arithmetic number, because the mean of its divisors is an integer number (15037071).

Almost surely, 2^51555668 is an apocalyptic number.

It is an amenable number.

51555668 is a deficient number, since it is larger than the sum of its proper divisors (38666758).

51555668 is a wasteful number, since it uses less digits than its factorization.

51555668 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12888921 (or 12888919 counting only the distinct ones).

The product of its digits is 180000, while the sum is 41.

The square root of 51555668 is about 7180.2275729952. The cubic root of 51555668 is about 372.1849486929.

The spelling of 51555668 in words is "fifty-one million, five hundred fifty-five thousand, six hundred sixty-eight".