51401381 has 2 divisors, whose sum is σ = 51401382. Its totient is φ = 51401380.

The previous prime is 51401377. The next prime is 51401393. The reversal of 51401381 is 18310415.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 34869025 + 16532356 = 5905^2 + 4066^2 .

It is a cyclic number.

It is not a de Polignac number, because 51401381 - 2² = 51401377 is a prime.

It is a super-2 number, since 2×51401381² = 5284203937414322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51401881) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25700690 + 25700691.

It is an arithmetic number, because the mean of its divisors is an integer number (25700691).

Almost surely, 2^51401381 is an apocalyptic number.

It is an amenable number.

51401381 is a deficient number, since it is larger than the sum of its proper divisors (1).

51401381 is an equidigital number, since it uses as much as digits as its factorization.

51401381 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 480, while the sum is 23.

The square root of 51401381 is about 7169.4756433089. The cubic root of 51401381 is about 371.8133071964.

Adding to 51401381 its reverse (18310415), we get a palindrome (69711796).

The spelling of 51401381 in words is "fifty-one million, four hundred one thousand, three hundred eighty-one".