50399981 has 2 divisors, whose sum is σ = 50399982. Its totient is φ = 50399980.

The previous prime is 50399963. The next prime is 50400001. The reversal of 50399981 is 18999305.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 47141956 + 3258025 = 6866^2 + 1805^2 .

It is a cyclic number.

It is not a de Polignac number, because 50399981 - 2¹⁸ = 50137837 is a prime.

It is a super-2 number, since 2×50399981² = 5080316169600722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (50399081) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25199990 + 25199991.

It is an arithmetic number, because the mean of its divisors is an integer number (25199991).

Almost surely, 2^50399981 is an apocalyptic number.

It is an amenable number.

50399981 is a deficient number, since it is larger than the sum of its proper divisors (1).

50399981 is an equidigital number, since it uses as much as digits as its factorization.

50399981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 87480, while the sum is 44.

The square root of 50399981 is about 7099.2944015585. The cubic root of 50399981 is about 369.3829036724.

The spelling of 50399981 in words is "fifty million, three hundred ninety-nine thousand, nine hundred eighty-one".