391638053 has 2 divisors, whose sum is σ = 391638054. Its totient is φ = 391638052.

The previous prime is 391638031. The next prime is 391638077. The reversal of 391638053 is 350836193.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 361684324 + 29953729 = 19018^2 + 5473^2 .

It is a cyclic number.

It is not a de Polignac number, because 391638053 - 2¹⁴ = 391621669 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 391637998 and 391638016.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (391638553) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 195819026 + 195819027.

It is an arithmetic number, because the mean of its divisors is an integer number (195819027).

Almost surely, 2^391638053 is an apocalyptic number.

It is an amenable number.

391638053 is a deficient number, since it is larger than the sum of its proper divisors (1).

391638053 is an equidigital number, since it uses as much as digits as its factorization.

391638053 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 58320, while the sum is 38.

The square root of 391638053 is about 19789.8472202289. The cubic root of 391638053 is about 731.6358218384.

The spelling of 391638053 in words is "three hundred ninety-one million, six hundred thirty-eight thousand, fifty-three".