20724259 has 2 divisors, whose sum is σ = 20724260. Its totient is φ = 20724258.

The previous prime is 20724257. The next prime is 20724287. The reversal of 20724259 is 95242702.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20724259 - 2¹ = 20724257 is a prime.

It is a super-2 number, since 2×20724259² = 858989822198162, which contains 22 as substring.

Together with 20724257, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 20724259.

It is not a weakly prime, because it can be changed into another prime (20724251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10362129 + 10362130.

It is an arithmetic number, because the mean of its divisors is an integer number (10362130).

Almost surely, 2^20724259 is an apocalyptic number.

20724259 is a deficient number, since it is larger than the sum of its proper divisors (1).

20724259 is an equidigital number, since it uses as much as digits as its factorization.

20724259 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10080, while the sum is 31.

The square root of 20724259 is about 4552.3904709504. The cubic root of 20724259 is about 274.6795562245.

The spelling of 20724259 in words is "twenty million, seven hundred twenty-four thousand, two hundred fifty-nine".