1990100 has 36 divisors (see below), whose sum is σ = 4937184. Its totient is φ = 682080.

The previous prime is 1990081. The next prime is 1990103. The reversal of 1990100 is 10991.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1990103) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 722 + ... + 2121.

It is an arithmetic number, because the mean of its divisors is an integer number (137144).

2^1990100 is an apocalyptic number.

1990100 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1990100 is an abundant number, since it is smaller than the sum of its proper divisors (2947084).

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

1990100 is a wasteful number, since it uses less digits than its factorization.

1990100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2864 (or 2857 counting only the distinct ones).

The product of its (nonzero) digits is 81, while the sum is 20.

The square root of 1990100 is about 1410.7090415816. The cubic root of 1990100 is about 125.7838740563.

The spelling of 1990100 in words is "one million, nine hundred ninety thousand, one hundred".