51421663 has 4 divisors (see below), whose sum is σ = 51511360. Its totient is φ = 51331968.

The previous prime is 51421649. The next prime is 51421687. The reversal of 51421663 is 36612415.

51421663 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is not a de Polignac number, because 51421663 - 2⁵ = 51421631 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51421603) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 43983 + ... + 45136.

It is an arithmetic number, because the mean of its divisors is an integer number (12877840).

Almost surely, 2^51421663 is an apocalyptic number.

51421663 is a deficient number, since it is larger than the sum of its proper divisors (89697).

51421663 is an equidigital number, since it uses as much as digits as its factorization.

51421663 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 89696.

The product of its digits is 4320, while the sum is 28.

The square root of 51421663 is about 7170.8899726603. The cubic root of 51421663 is about 371.8622042345.

The spelling of 51421663 in words is "fifty-one million, four hundred twenty-one thousand, six hundred sixty-three".