1669612820 has 24 divisors (see below), whose sum is σ = 3540905928. Its totient is φ = 661232000.

The previous prime is 1669612807. The next prime is 1669612829. The reversal of 1669612820 is 282169661.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 512388496 + 1157224324 = 22636^2 + 34018^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1669612829) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 411251 + ... + 415290.

It is an arithmetic number, because the mean of its divisors is an integer number (147537747).

Almost surely, 2^1669612820 is an apocalyptic number.

1669612820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1669612820 is an abundant number, since it is smaller than the sum of its proper divisors (1871293108).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1669612820 is a wasteful number, since it uses less digits than its factorization.

1669612820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 826651 (or 826649 counting only the distinct ones).

The product of its (nonzero) digits is 62208, while the sum is 41.

The square root of 1669612820 is about 40860.8959764712. The cubic root of 1669612820 is about 1186.3293004623.

The spelling of 1669612820 in words is "one billion, six hundred sixty-nine million, six hundred twelve thousand, eight hundred twenty".