20724151 has 16 divisors (see below), whose sum is σ = 25028608. Its totient is φ = 16783200.

The previous prime is 20724097. The next prime is 20724161. The reversal of 20724151 is 15142702.

20724151 = 1856² + 1857² + ... + 1861².

It is a happy number.

It is not a de Polignac number, because 20724151 - 2⁹ = 20723639 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20724161) 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, 8221 + ... + 10441.

It is an arithmetic number, because the mean of its divisors is an integer number (1564288).

Almost surely, 2^20724151 is an apocalyptic number.

20724151 is a deficient number, since it is larger than the sum of its proper divisors (4304457).

20724151 is a wasteful number, since it uses less digits than its factorization.

20724151 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2302.

The product of its (nonzero) digits is 560, while the sum is 22.

The square root of 20724151 is about 4552.3786090351. The cubic root of 20724151 is about 274.6790790793.

Adding to 20724151 its reverse (15142702), we get a palindrome (35866853).

The spelling of 20724151 in words is "twenty million, seven hundred twenty-four thousand, one hundred fifty-one".