51271621 has 2 divisors, whose sum is σ = 51271622. Its totient is φ = 51271620.

The previous prime is 51271589. The next prime is 51271631. The reversal of 51271621 is 12617215.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 49350625 + 1920996 = 7025^2 + 1386^2 .

It is a cyclic number.

It is not a de Polignac number, because 51271621 - 2⁵ = 51271589 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51271631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25635810 + 25635811.

It is an arithmetic number, because the mean of its divisors is an integer number (25635811).

Almost surely, 2^51271621 is an apocalyptic number.

It is an amenable number.

51271621 is a deficient number, since it is larger than the sum of its proper divisors (1).

51271621 is an equidigital number, since it uses as much as digits as its factorization.

51271621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 840, while the sum is 25.

The square root of 51271621 is about 7160.4204485491. The cubic root of 51271621 is about 371.5001693689.

Adding to 51271621 its reverse (12617215), we get a palindrome (63888836).

The spelling of 51271621 in words is "fifty-one million, two hundred seventy-one thousand, six hundred twenty-one".