51421213 has 2 divisors, whose sum is σ = 51421214. Its totient is φ = 51421212.

The previous prime is 51421193. The next prime is 51421217. The reversal of 51421213 is 31212415.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 49028004 + 2393209 = 7002^2 + 1547^2 .

It is a cyclic number.

It is not a de Polignac number, because 51421213 - 2⁹ = 51420701 is a prime.

It is a super-2 number, since 2×51421213² = 5288282292782738, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51421217) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25710606 + 25710607.

It is an arithmetic number, because the mean of its divisors is an integer number (25710607).

Almost surely, 2^51421213 is an apocalyptic number.

It is an amenable number.

51421213 is a deficient number, since it is larger than the sum of its proper divisors (1).

51421213 is an equidigital number, since it uses as much as digits as its factorization.

51421213 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 240, while the sum is 19.

The square root of 51421213 is about 7170.8585957331. The cubic root of 51421213 is about 371.8611194876.

Adding to 51421213 its reverse (31212415), we get a palindrome (82633628).

The spelling of 51421213 in words is "fifty-one million, four hundred twenty-one thousand, two hundred thirteen".