298388021 has 4 divisors (see below), whose sum is σ = 298424844. Its totient is φ = 298351200.

The previous prime is 298388003. The next prime is 298388053. The reversal of 298388021 is 120883892.

298388021 = 12214² + 12215².

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 149181796 + 149206225 = 12214^2 + 12215^2 .

It is a cyclic number.

It is not a de Polignac number, because 298388021 - 2²⁶ = 231279157 is a prime.

It is a super-2 number, since 2×298388021² = 178070822152592882, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 298388021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (298388621) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 350 + ... + 24431.

It is an arithmetic number, because the mean of its divisors is an integer number (74606211).

Almost surely, 2^298388021 is an apocalyptic number.

298388021 is the 12215-th centered square number.

It is an amenable number.

298388021 is a deficient number, since it is larger than the sum of its proper divisors (36823).

298388021 is a wasteful number, since it uses less digits than its factorization.

298388021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36822.

The product of its (nonzero) digits is 55296, while the sum is 41.

The square root of 298388021 is about 17273.9115720789. The cubic root of 298388021 is about 668.2317829356.

The spelling of 298388021 in words is "two hundred ninety-eight million, three hundred eighty-eight thousand, twenty-one".