618937381 has 2 divisors, whose sum is σ = 618937382. Its totient is φ = 618937380.

The previous prime is 618937321. The next prime is 618937427. The reversal of 618937381 is 183739816.

It is an a-pointer prime, because the next prime (618937427) can be obtained adding 618937381 to its sum of digits (46).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 491021281 + 127916100 = 22159^2 + 11310^2 .

It is a cyclic number.

It is not a de Polignac number, because 618937381 - 2⁹ = 618936869 is a prime.

It is a super-2 number, since 2×618937381² = 766166963198278322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (618937301) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 309468690 + 309468691.

It is an arithmetic number, because the mean of its divisors is an integer number (309468691).

Almost surely, 2^618937381 is an apocalyptic number.

It is an amenable number.

618937381 is a deficient number, since it is larger than the sum of its proper divisors (1).

618937381 is an equidigital number, since it uses as much as digits as its factorization.

618937381 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 217728, while the sum is 46.

The square root of 618937381 is about 24878.4521423661. The cubic root of 618937381 is about 852.2144707014.

The spelling of 618937381 in words is "six hundred eighteen million, nine hundred thirty-seven thousand, three hundred eighty-one".