21329761 has 8 divisors (see below), whose sum is σ = 23227200. Its totient is φ = 19509840.

The previous prime is 21329719. The next prime is 21329773. The reversal of 21329761 is 16792312.

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

It is a cyclic number.

It is not a de Polignac number, because 21329761 - 2¹⁵ = 21296993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21323761) 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, 18805 + ... + 19906.

It is an arithmetic number, because the mean of its divisors is an integer number (2903400).

Almost surely, 2^21329761 is an apocalyptic number.

It is an amenable number.

21329761 is a deficient number, since it is larger than the sum of its proper divisors (1897439).

21329761 is a wasteful number, since it uses less digits than its factorization.

21329761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38759.

The product of its digits is 4536, while the sum is 31.

The square root of 21329761 is about 4618.4154208993. The cubic root of 21329761 is about 277.3290281411.

The spelling of 21329761 in words is "twenty-one million, three hundred twenty-nine thousand, seven hundred sixty-one".