20120724 has 120 divisors (see below), whose sum is σ = 60191208. Its totient is φ = 5806080.

The previous prime is 20120719. The next prime is 20120729. The reversal of 20120724 is 42702102.

It is an interprime number because it is at equal distance from previous prime (20120719) and next prime (20120729).

It can be written as a sum of positive squares in 4 ways, for example, as 3572100 + 16548624 = 1890^2 + 4068^2 .

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 = 20120697 and 20120706.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20120729) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 71464 + ... + 71744.

Almost surely, 2^20120724 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20120724, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30095604).

20120724 is an abundant number, since it is smaller than the sum of its proper divisors (40070484).

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

20120724 is a wasteful number, since it uses less digits than its factorization.

20120724 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 327 (or 316 counting only the distinct ones).

The product of its (nonzero) digits is 224, while the sum is 18.

The square root of 20120724 is about 4485.6130015863. The cubic root of 20120724 is about 271.9868253423.

Adding to 20120724 its reverse (42702102), we get a palindrome (62822826).

The spelling of 20120724 in words is "twenty million, one hundred twenty thousand, seven hundred twenty-four".