1669921890 has 64 divisors (see below), whose sum is σ = 4932700416. Its totient is φ = 352334592.

The previous prime is 1669921889. The next prime is 1669921901. The reversal of 1669921890 is 981299661.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 303117 + ... + 308576.

It is an arithmetic number, because the mean of its divisors is an integer number (77073444).

Almost surely, 2^1669921890 is an apocalyptic number.

1669921890 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1669921890 is an abundant number, since it is smaller than the sum of its proper divisors (3262778526).

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

1669921890 is a wasteful number, since it uses less digits than its factorization.

1669921890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 611723.

The product of its (nonzero) digits is 419904, while the sum is 51.

The square root of 1669921890 is about 40864.6777792264. The cubic root of 1669921890 is about 1186.4024983059.

The spelling of 1669921890 in words is "one billion, six hundred sixty-nine million, nine hundred twenty-one thousand, eight hundred ninety".