20432720 has 160 divisors (see below), whose sum is σ = 61710336. Its totient is φ = 6105600.

The previous prime is 20432707. The next prime is 20432729. The reversal of 20432720 is 2723402.

It is a happy number.

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

It is a junction number, because it is equal to n+sod(n) for n = 20432692 and 20432701.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20432729) 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 31 ways as a sum of consecutive naturals, for example, 190907 + ... + 191013.

Almost surely, 2^20432720 is an apocalyptic number.

20432720 is a gapful number since it is divisible by the number (20) 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 20432720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30855168).

20432720 is an abundant number, since it is smaller than the sum of its proper divisors (41277616).

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

20432720 is a wasteful number, since it uses less digits than its factorization.

20432720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 169 (or 163 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 20.

The square root of 20432720 is about 4520.2566298829. The cubic root of 20432720 is about 273.3854484540.

The spelling of 20432720 in words is "twenty million, four hundred thirty-two thousand, seven hundred twenty".