21433155 has 16 divisors (see below), whose sum is σ = 34566144. Its totient is φ = 11340000.

The previous prime is 21433151. The next prime is 21433163. The reversal of 21433155 is 55133412.

It is not a de Polignac number, because 21433155 - 2² = 21433151 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21433151) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3721 + ... + 7530.

It is an arithmetic number, because the mean of its divisors is an integer number (2160384).

Almost surely, 2^21433155 is an apocalyptic number.

21433155 is a deficient number, since it is larger than the sum of its proper divisors (13132989).

21433155 is a wasteful number, since it uses less digits than its factorization.

21433155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11386.

The product of its digits is 1800, while the sum is 24.

The square root of 21433155 is about 4629.5955546894. The cubic root of 21433155 is about 277.7764147785.

Adding to 21433155 its reverse (55133412), we get a palindrome (76566567).

The spelling of 21433155 in words is "twenty-one million, four hundred thirty-three thousand, one hundred fifty-five".