51391601 has 2 divisors, whose sum is σ = 51391602. Its totient is φ = 51391600.

The previous prime is 51391597. The next prime is 51391619. The reversal of 51391601 is 10619315.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 44209201 + 7182400 = 6649^2 + 2680^2 .

It is a cyclic number.

It is not a de Polignac number, because 51391601 - 2² = 51391597 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (51391621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25695800 + 25695801.

It is an arithmetic number, because the mean of its divisors is an integer number (25695801).

Almost surely, 2^51391601 is an apocalyptic number.

It is an amenable number.

51391601 is a deficient number, since it is larger than the sum of its proper divisors (1).

51391601 is an equidigital number, since it uses as much as digits as its factorization.

51391601 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 810, while the sum is 26.

The square root of 51391601 is about 7168.7935526140. The cubic root of 51391601 is about 371.7897244008.

The spelling of 51391601 in words is "fifty-one million, three hundred ninety-one thousand, six hundred one".