21151229 has 8 divisors (see below), whose sum is σ = 23129472. Its totient is φ = 19182240.

The previous prime is 21151219. The next prime is 21151241. The reversal of 21151229 is 92215112.

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

It is a de Polignac number, because none of the positive numbers 2^k-21151229 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21151219) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3017 + ... + 7169.

It is an arithmetic number, because the mean of its divisors is an integer number (2891184).

Almost surely, 2^21151229 is an apocalyptic number.

It is an amenable number.

21151229 is a deficient number, since it is larger than the sum of its proper divisors (1978243).

21151229 is a wasteful number, since it uses less digits than its factorization.

21151229 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4627.

The product of its digits is 360, while the sum is 23.

The square root of 21151229 is about 4599.0465316194. The cubic root of 21151229 is about 276.5531030184.

The spelling of 21151229 in words is "twenty-one million, one hundred fifty-one thousand, two hundred twenty-nine".