21553713 has 12 divisors (see below), whose sum is σ = 31181748. Its totient is φ = 14346720.

The previous prime is 21553643. The next prime is 21553717. The reversal of 21553713 is 31735512.

It can be written as a sum of positive squares in 2 ways, for example, as 16064064 + 5489649 = 4008^2 + 2343^2 .

It is not a de Polignac number, because 21553713 - 2¹⁷ = 21422641 is a prime.

It is a super-3 number, since 3×21553713³ (a number of 23 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (21553717) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5931 + ... + 8847.

It is an arithmetic number, because the mean of its divisors is an integer number (2598479).

Almost surely, 2^21553713 is an apocalyptic number.

It is an amenable number.

21553713 is a deficient number, since it is larger than the sum of its proper divisors (9628035).

21553713 is a wasteful number, since it uses less digits than its factorization.

21553713 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3744 (or 3741 counting only the distinct ones).

The product of its digits is 3150, while the sum is 27.

The square root of 21553713 is about 4642.5976564850. The cubic root of 21553713 is about 278.2962569886.

The spelling of 21553713 in words is "twenty-one million, five hundred fifty-three thousand, seven hundred thirteen".