51368921 has 2 divisors, whose sum is σ = 51368922. Its totient is φ = 51368920.

The previous prime is 51368887. The next prime is 51368923. The reversal of 51368921 is 12986315.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 29278921 + 22090000 = 5411^2 + 4700^2 .

It is a cyclic number.

It is not a de Polignac number, because 51368921 - 2⁶ = 51368857 is a prime.

Together with 51368923, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (51368923) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25684460 + 25684461.

It is an arithmetic number, because the mean of its divisors is an integer number (25684461).

Almost surely, 2^51368921 is an apocalyptic number.

It is an amenable number.

51368921 is a deficient number, since it is larger than the sum of its proper divisors (1).

51368921 is an equidigital number, since it uses as much as digits as its factorization.

51368921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12960, while the sum is 35.

The square root of 51368921 is about 7167.2115219240. The cubic root of 51368921 is about 371.7350239471.

The spelling of 51368921 in words is "fifty-one million, three hundred sixty-eight thousand, nine hundred twenty-one".