20724261 has 16 divisors (see below), whose sum is σ = 28252800. Its totient is φ = 13509440.

The previous prime is 20724259. The next prime is 20724287. The reversal of 20724261 is 16242702.

It is a cyclic number.

It is not a de Polignac number, because 20724261 - 2¹ = 20724259 is a prime.

It is a super-2 number, since 2×20724261² = 858989987992242, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20724211) 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, 31411 + ... + 32063.

It is an arithmetic number, because the mean of its divisors is an integer number (1765800).

Almost surely, 2^20724261 is an apocalyptic number.

It is an amenable number.

20724261 is a deficient number, since it is larger than the sum of its proper divisors (7528539).

20724261 is a wasteful number, since it uses less digits than its factorization.

20724261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 876.

The product of its (nonzero) digits is 1344, while the sum is 24.

The square root of 20724261 is about 4552.3906906152. The cubic root of 20724261 is about 274.6795650605.

Adding to 20724261 its reverse (16242702), we get a palindrome (36966963).

The spelling of 20724261 in words is "twenty million, seven hundred twenty-four thousand, two hundred sixty-one".