20724955 has 16 divisors (see below), whose sum is σ = 27480384. Its totient is φ = 14924800.

The previous prime is 20724943. The next prime is 20724959. The reversal of 20724955 is 55942702.

It is not a de Polignac number, because 20724955 - 2⁷ = 20724827 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20724955.

It is not an unprimeable number, because it can be changed into a prime (20724959) 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, 3346 + ... + 7255.

It is an arithmetic number, because the mean of its divisors is an integer number (1717524).

Almost surely, 2^20724955 is an apocalyptic number.

20724955 is a deficient number, since it is larger than the sum of its proper divisors (6755429).

20724955 is a wasteful number, since it uses less digits than its factorization.

20724955 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10646.

The product of its (nonzero) digits is 25200, while the sum is 34.

The square root of 20724955 is about 4552.4669136634. The cubic root of 20724955 is about 274.6826311206.

The spelling of 20724955 in words is "twenty million, seven hundred twenty-four thousand, nine hundred fifty-five".