21329377 has 2 divisors, whose sum is σ = 21329378. Its totient is φ = 21329376.

The previous prime is 21329311. The next prime is 21329401. The reversal of 21329377 is 77392312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16329681 + 4999696 = 4041^2 + 2236^2 .

It is a cyclic number.

It is not a de Polignac number, because 21329377 - 2¹⁹ = 20805089 is a prime.

It is not a weakly prime, because it can be changed into another prime (21329177) 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 as a sum of consecutive naturals, namely, 10664688 + 10664689.

It is an arithmetic number, because the mean of its divisors is an integer number (10664689).

Almost surely, 2^21329377 is an apocalyptic number.

It is an amenable number.

21329377 is a deficient number, since it is larger than the sum of its proper divisors (1).

21329377 is an equidigital number, since it uses as much as digits as its factorization.

21329377 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 15876, while the sum is 34.

The square root of 21329377 is about 4618.3738480119. The cubic root of 21329377 is about 277.3273638783.

The spelling of 21329377 in words is "twenty-one million, three hundred twenty-nine thousand, three hundred seventy-seven".