15820020 has 72 divisors (see below), whose sum is σ = 48353760. Its totient is φ = 4186560.

The previous prime is 15819977. The next prime is 15820037. The reversal of 15820020 is 2002851.

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

It is a junction number, because it is equal to n+sod(n) for n = 15819975 and 15820002.

It is a congruent number.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 31975 + ... + 32465.

It is an arithmetic number, because the mean of its divisors is an integer number (671580).

Almost surely, 2^15820020 is an apocalyptic number.

15820020 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 15820020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24176880).

15820020 is an abundant number, since it is smaller than the sum of its proper divisors (32533740).

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

15820020 is a wasteful number, since it uses less digits than its factorization.

15820020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 685 (or 680 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 18.

The square root of 15820020 is about 3977.4388744517. The cubic root of 15820020 is about 251.0358091373.

Adding to 15820020 its reverse (2002851), we get a palindrome (17822871).

The spelling of 15820020 in words is "fifteen million, eight hundred twenty thousand, twenty".