20001870 has 128 divisors (see below), whose sum is σ = 64281600. Its totient is φ = 4323456.

The previous prime is 20001853. The next prime is 20001899. The reversal of 20001870 is 7810002.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

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 63 ways as a sum of consecutive naturals, for example, 35632 + ... + 36188.

It is an arithmetic number, because the mean of its divisors is an integer number (502200).

Almost surely, 2^20001870 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20001870, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32140800).

20001870 is an abundant number, since it is smaller than the sum of its proper divisors (44279730).

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

20001870 is a wasteful number, since it uses less digits than its factorization.

20001870 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 599 (or 593 counting only the distinct ones).

The product of its (nonzero) digits is 112, while the sum is 18.

The square root of 20001870 is about 4472.3450224686. The cubic root of 20001870 is about 271.4502213307.

Adding to 20001870 its reverse (7810002), we get a palindrome (27811872).

The spelling of 20001870 in words is "twenty million, one thousand, eight hundred seventy".