20159720 has 32 divisors (see below), whose sum is σ = 51840000. Its totient is φ = 6911808.

The previous prime is 20159719. The next prime is 20159723. The reversal of 20159720 is 2795102.

It is a self number, because there is not a number n which added to its sum of digits gives 20159720.

It is not an unprimeable number, because it can be changed into a prime (20159723) 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 7 ways as a sum of consecutive naturals, for example, 35720 + ... + 36279.

It is an arithmetic number, because the mean of its divisors is an integer number (1620000).

Almost surely, 2^20159720 is an apocalyptic number.

20159720 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20159720 is an abundant number, since it is smaller than the sum of its proper divisors (31680280).

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

20159720 is a wasteful number, since it uses less digits than its factorization.

20159720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72017 (or 72013 counting only the distinct ones).

The product of its (nonzero) digits is 1260, while the sum is 26.

The square root of 20159720 is about 4489.9576835422. The cubic root of 20159720 is about 272.1624246152.

The spelling of 20159720 in words is "twenty million, one hundred fifty-nine thousand, seven hundred twenty".