518196421 has 2 divisors, whose sum is σ = 518196422. Its totient is φ = 518196420.

The previous prime is 518196409. The next prime is 518196439. The reversal of 518196421 is 124691815.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 267322500 + 250873921 = 16350^2 + 15839^2 .

It is a cyclic number.

It is not a de Polignac number, because 518196421 - 2¹¹ = 518194373 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (518196401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 259098210 + 259098211.

It is an arithmetic number, because the mean of its divisors is an integer number (259098211).

Almost surely, 2^518196421 is an apocalyptic number.

It is an amenable number.

518196421 is a deficient number, since it is larger than the sum of its proper divisors (1).

518196421 is an equidigital number, since it uses as much as digits as its factorization.

518196421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 17280, while the sum is 37.

The square root of 518196421 is about 22763.9280661313. The cubic root of 518196421 is about 803.2143700877.

The spelling of 518196421 in words is "five hundred eighteen million, one hundred ninety-six thousand, four hundred twenty-one".