51005566 has 4 divisors (see below), whose sum is σ = 76508352. Its totient is φ = 25502782.

The previous prime is 51005561. The next prime is 51005567. The reversal of 51005566 is 66550015.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51005561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12751390 + ... + 12751393.

It is an arithmetic number, because the mean of its divisors is an integer number (19127088).

Almost surely, 2^51005566 is an apocalyptic number.

51005566 is a deficient number, since it is larger than the sum of its proper divisors (25502786).

51005566 is a wasteful number, since it uses less digits than its factorization.

51005566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25502785.

The product of its (nonzero) digits is 4500, while the sum is 28.

The square root of 51005566 is about 7141.8181158582. The cubic root of 51005566 is about 370.8564673640.

The spelling of 51005566 in words is "fifty-one million, five thousand, five hundred sixty-six".