20724471 has 16 divisors (see below), whose sum is σ = 30904800. Its totient is φ = 13725504.

The previous prime is 20724467. The next prime is 20724491. The reversal of 20724471 is 17442702.

It is a happy number.

It is not a de Polignac number, because 20724471 - 2² = 20724467 is a prime.

It is a super-3 number, since 3×20724471³ (a number of 23 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20724491) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1795 + ... + 6683.

It is an arithmetic number, because the mean of its divisors is an integer number (1931550).

Almost surely, 2^20724471 is an apocalyptic number.

20724471 is a deficient number, since it is larger than the sum of its proper divisors (10180329).

20724471 is a wasteful number, since it uses less digits than its factorization.

20724471 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5055 (or 5049 counting only the distinct ones).

The product of its (nonzero) digits is 3136, while the sum is 27.

The square root of 20724471 is about 4552.4137553610. The cubic root of 20724471 is about 274.6804928381.

The spelling of 20724471 in words is "twenty million, seven hundred twenty-four thousand, four hundred seventy-one".