918938421 has 6 divisors (see below), whose sum is σ = 1327355510. Its totient is φ = 612625608.

The previous prime is 918938413. The next prime is 918938437. The reversal of 918938421 is 124839819.

It can be written as a sum of positive squares in only one way, i.e., 716900625 + 202037796 = 26775^2 + 14214^2 .

It is not a de Polignac number, because 918938421 - 2³ = 918938413 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (918938491) 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 in 5 ways as a sum of consecutive naturals, for example, 51052126 + ... + 51052143.

Almost surely, 2^918938421 is an apocalyptic number.

It is an amenable number.

918938421 is a deficient number, since it is larger than the sum of its proper divisors (408417089).

918938421 is a wasteful number, since it uses less digits than its factorization.

918938421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102104275 (or 102104272 counting only the distinct ones).

The product of its digits is 124416, while the sum is 45.

The square root of 918938421 is about 30313.9971135448. The cubic root of 918938421 is about 972.2145953308.

The spelling of 918938421 in words is "nine hundred eighteen million, nine hundred thirty-eight thousand, four hundred twenty-one".