20712240 has 160 divisors (see below), whose sum is σ = 73328640. Its totient is φ = 5370624.

The previous prime is 20712227. The next prime is 20712253. The reversal of 20712240 is 4221702.

It is an interprime number because it is at equal distance from previous prime (20712227) and next prime (20712253).

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

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 92769 + ... + 92991.

It is an arithmetic number, because the mean of its divisors is an integer number (458304).

Almost surely, 2^20712240 is an apocalyptic number.

20712240 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 20712240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36664320).

20712240 is an abundant number, since it is smaller than the sum of its proper divisors (52616400).

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

20712240 is a wasteful number, since it uses less digits than its factorization.

20712240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 288 (or 276 counting only the distinct ones).

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

The square root of 20712240 is about 4551.0702038092. The cubic root of 20712240 is about 274.6264459701.

Adding to 20712240 its reverse (4221702), we get a palindrome (24933942).

The spelling of 20712240 in words is "twenty million, seven hundred twelve thousand, two hundred forty".