21380529 has 8 divisors (see below), whose sum is σ = 30007840. Its totient is φ = 13503456.

The previous prime is 21380521. The next prime is 21380539. The reversal of 21380529 is 92508312.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21380529 - 2³ = 21380521 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21380496 and 21380505.

It is not an unprimeable number, because it can be changed into a prime (21380521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 187492 + ... + 187605.

It is an arithmetic number, because the mean of its divisors is an integer number (3750980).

Almost surely, 2^21380529 is an apocalyptic number.

It is an amenable number.

21380529 is a deficient number, since it is larger than the sum of its proper divisors (8627311).

21380529 is a wasteful number, since it uses less digits than its factorization.

21380529 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 375119.

The product of its (nonzero) digits is 4320, while the sum is 30.

The square root of 21380529 is about 4623.9084117227. The cubic root of 21380529 is about 277.5488819010.

The spelling of 21380529 in words is "twenty-one million, three hundred eighty thousand, five hundred twenty-nine".