20430072 has 144 divisors (see below), whose sum is σ = 63376560. Its totient is φ = 5930496.

The previous prime is 20430071. The next prime is 20430077. The reversal of 20430072 is 27003402.

It is a happy number.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20430071) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 279828 + ... + 279900.

It is an arithmetic number, because the mean of its divisors is an integer number (440115).

Almost surely, 2^20430072 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 20430072, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31688280).

20430072 is an abundant number, since it is smaller than the sum of its proper divisors (42946488).

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

20430072 is a wasteful number, since it uses less digits than its factorization.

20430072 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 134 (or 114 counting only the distinct ones).

The product of its (nonzero) digits is 336, while the sum is 18.

The square root of 20430072 is about 4519.9637166685. The cubic root of 20430072 is about 273.3736380515.

Adding to 20430072 its reverse (27003402), we get a palindrome (47433474).

It can be divided in two parts, 204 and 30072, that added together give a square (30276 = 174²).

The spelling of 20430072 in words is "twenty million, four hundred thirty thousand, seventy-two".