398521369 has 3 divisors (see below), whose sum is σ = 398541333. Its totient is φ = 398501406.

The previous prime is 398521351. The next prime is 398521433. The reversal of 398521369 is 963125893.

It is a happy number.

The square root of 398521369 is 19963.

It is a perfect power (a square), and thus also a powerful 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 is not a de Polignac number, because 398521369 - 2¹⁷ = 398390297 is a prime.

It is a super-2 number, since 2×398521369² = 317638563099268322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (398521169) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 9982 + ... + 29944.

It is an arithmetic number, because the mean of its divisors is an integer number (132847111).

Almost surely, 2^398521369 is an apocalyptic number.

398521369 is the 19963-rd square number.

398521369 is the 9982-nd centered octagonal number.

It is an amenable number.

398521369 is a deficient number, since it is larger than the sum of its proper divisors (19964).

398521369 is an frugal number, since it uses more digits than its factorization.

398521369 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39926 (or 19963 counting only the distinct ones).

The product of its digits is 349920, while the sum is 46.

The cubic root of 398521369 is about 735.8972915367.

The spelling of 398521369 in words is "three hundred ninety-eight million, five hundred twenty-one thousand, three hundred sixty-nine".