51478421 has 2 divisors, whose sum is σ = 51478422. Its totient is φ = 51478420.

The previous prime is 51478417. The next prime is 51478459. The reversal of 51478421 is 12487415.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 35164900 + 16313521 = 5930^2 + 4039^2 .

It is a cyclic number.

It is not a de Polignac number, because 51478421 - 2² = 51478417 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 (51478481) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25739210 + 25739211.

It is an arithmetic number, because the mean of its divisors is an integer number (25739211).

Almost surely, 2^51478421 is an apocalyptic number.

It is an amenable number.

51478421 is a deficient number, since it is larger than the sum of its proper divisors (1).

51478421 is an equidigital number, since it uses as much as digits as its factorization.

51478421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8960, while the sum is 32.

The square root of 51478421 is about 7174.8464095059. The cubic root of 51478421 is about 371.9989714582.

The spelling of 51478421 in words is "fifty-one million, four hundred seventy-eight thousand, four hundred twenty-one".