51553421 has 2 divisors, whose sum is σ = 51553422. Its totient is φ = 51553420.

The previous prime is 51553417. The next prime is 51553451. The reversal of 51553421 is 12435515.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 35832196 + 15721225 = 5986^2 + 3965^2 .

It is a cyclic number.

It is not a de Polignac number, because 51553421 - 2² = 51553417 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51553451) 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 as a sum of consecutive naturals, namely, 25776710 + 25776711.

It is an arithmetic number, because the mean of its divisors is an integer number (25776711).

Almost surely, 2^51553421 is an apocalyptic number.

It is an amenable number.

51553421 is a deficient number, since it is larger than the sum of its proper divisors (1).

51553421 is an equidigital number, since it uses as much as digits as its factorization.

51553421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3000, while the sum is 26.

The square root of 51553421 is about 7180.0710999265. The cubic root of 51553421 is about 372.1795415168.

Adding to 51553421 its reverse (12435515), we get a palindrome (63988936).

The spelling of 51553421 in words is "fifty-one million, five hundred fifty-three thousand, four hundred twenty-one".