820421450 has 48 divisors (see below), whose sum is σ = 1576445976. Its totient is φ = 317491200.

The previous prime is 820421447. The next prime is 820421509. The reversal of 820421450 is 54124028.

It is a happy number.

It is a Cunningham number, because it is equal to 28643²+1.

It can be written as a sum of positive squares in 12 ways, for example, as 365153881 + 455267569 = 19109^2 + 21337^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 191330 + ... + 195570.

Almost surely, 2^820421450 is an apocalyptic number.

820421450 is a deficient number, since it is larger than the sum of its proper divisors (756024526).

820421450 is a wasteful number, since it uses less digits than its factorization.

820421450 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4379 (or 4374 counting only the distinct ones).

The product of its (nonzero) digits is 2560, while the sum is 26.

The square root of 820421450 is about 28643.0000174563. Note that the first 4 decimals coincide. The cubic root of 820421450 is about 936.1504897497.

Adding to 820421450 its reverse (54124028), we get a palindrome (874545478).

The spelling of 820421450 in words is "eight hundred twenty million, four hundred twenty-one thousand, four hundred fifty".