21159229 has 24 divisors (see below), whose sum is σ = 27004320. Its totient is φ = 16428384.

The previous prime is 21159223. The next prime is 21159247. The reversal of 21159229 is 92295112.

It is not a de Polignac number, because 21159229 - 2³ = 21159221 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21159229.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21159221) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 37302 + ... + 37864.

It is an arithmetic number, because the mean of its divisors is an integer number (1125180).

Almost surely, 2^21159229 is an apocalyptic number.

It is an amenable number.

21159229 is a deficient number, since it is larger than the sum of its proper divisors (5845091).

21159229 is a wasteful number, since it uses less digits than its factorization.

21159229 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 649 (or 642 counting only the distinct ones).

The product of its digits is 3240, while the sum is 31.

The square root of 21159229 is about 4599.9161948888. The cubic root of 21159229 is about 276.5879653890.

The spelling of 21159229 in words is "twenty-one million, one hundred fifty-nine thousand, two hundred twenty-nine".