21729301 has 6 divisors (see below), whose sum is σ = 23884406. Its totient is φ = 19753800.

The previous prime is 21729289. The next prime is 21729307. The reversal of 21729301 is 10392712.

It can be written as a sum of positive squares in only one way, i.e., 11553201 + 10176100 = 3399^2 + 3190^2 .

It is not a de Polignac number, because 21729301 - 2⁵ = 21729269 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 (21729307) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 89670 + ... + 89911.

Almost surely, 2^21729301 is an apocalyptic number.

It is an amenable number.

21729301 is a deficient number, since it is larger than the sum of its proper divisors (2155105).

21729301 is a wasteful number, since it uses less digits than its factorization.

21729301 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 179603 (or 179592 counting only the distinct ones).

The product of its (nonzero) digits is 756, while the sum is 25.

The square root of 21729301 is about 4661.4698325743. The cubic root of 21729301 is about 279.0499304702.

The spelling of 21729301 in words is "twenty-one million, seven hundred twenty-nine thousand, three hundred one".