51455399 has 2 divisors, whose sum is σ = 51455400. Its totient is φ = 51455398.

The previous prime is 51455377. The next prime is 51455423. The reversal of 51455399 is 99355415.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 51455399 - 2⁸ = 51455143 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51455699) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25727699 + 25727700.

It is an arithmetic number, because the mean of its divisors is an integer number (25727700).

Almost surely, 2^51455399 is an apocalyptic number.

51455399 is a deficient number, since it is larger than the sum of its proper divisors (1).

51455399 is an equidigital number, since it uses as much as digits as its factorization.

51455399 is an evil number, because the sum of its binary digits is even.

The product of its digits is 121500, while the sum is 41.

The square root of 51455399 is about 7173.2418751914. The cubic root of 51455399 is about 371.9435084950.

Adding to 51455399 its sum of digits (41), we get a triangular number (51455440 = T₁₀₁₄₄).

The spelling of 51455399 in words is "fifty-one million, four hundred fifty-five thousand, three hundred ninety-nine".