820421449 has 3 divisors (see below), whose sum is σ = 820450093. Its totient is φ = 820392806.

The previous prime is 820421447. The next prime is 820421509. The reversal of 820421449 is 944124028.

The square root of 820421449 is 28643.

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 820421449 - 2¹ = 820421447 is a prime.

It is a super-3 number, since 3×820421449³ (a number of 28 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (820421443) 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, 14322 + ... + 42964.

Almost surely, 2^820421449 is an apocalyptic number.

820421449 is the 28643-rd square number.

820421449 is the 14322-nd centered octagonal number.

It is an amenable number.

820421449 is a deficient number, since it is larger than the sum of its proper divisors (28644).

820421449 is an frugal number, since it uses more digits than its factorization.

820421449 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57286 (or 28643 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 34.

The cubic root of 820421449 is about 936.1504893694.

The spelling of 820421449 in words is "eight hundred twenty million, four hundred twenty-one thousand, four hundred forty-nine".