1669921020 has 216 divisors, whose sum is σ = 5525170560. Its totient is φ = 407773440.

The previous prime is 1669921013. The next prime is 1669921027. The reversal of 1669921020 is 201299661.

It is an interprime number because it is at equal distance from previous prime (1669921013) and next prime (1669921027).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1669921027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 2013966 + ... + 2014794.

Almost surely, 2^1669921020 is an apocalyptic number.

1669921020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1669921020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2762585280).

1669921020 is an abundant number, since it is smaller than the sum of its proper divisors (3855249540).

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

1669921020 is a wasteful number, since it uses less digits than its factorization.

1669921020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 913 (or 889 counting only the distinct ones).

The product of its (nonzero) digits is 11664, while the sum is 36.

The square root of 1669921020 is about 40864.6671343350. The cubic root of 1669921020 is about 1186.4022922743.

The spelling of 1669921020 in words is "one billion, six hundred sixty-nine million, nine hundred twenty-one thousand, twenty".