918874421 has 2 divisors, whose sum is σ = 918874422. Its totient is φ = 918874420.

The previous prime is 918874387. The next prime is 918874423. The reversal of 918874421 is 124478819.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 575328196 + 343546225 = 23986^2 + 18535^2 .

It is an emirp because it is prime and its reverse (124478819) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-918874421 is a prime.

Together with 918874423, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (918874423) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 459437210 + 459437211.

It is an arithmetic number, because the mean of its divisors is an integer number (459437211).

Almost surely, 2^918874421 is an apocalyptic number.

It is an amenable number.

918874421 is a deficient number, since it is larger than the sum of its proper divisors (1).

918874421 is an equidigital number, since it uses as much as digits as its factorization.

918874421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 129024, while the sum is 44.

The square root of 918874421 is about 30312.9414771975. The cubic root of 918874421 is about 972.1920246567.

The spelling of 918874421 in words is "nine hundred eighteen million, eight hundred seventy-four thousand, four hundred twenty-one".