21623133 has 32 divisors (see below), whose sum is σ = 35852544. Its totient is φ = 11308032.

The previous prime is 21623131. The next prime is 21623137. The reversal of 21623133 is 33132612.

It is not a de Polignac number, because 21623133 - 2¹ = 21623131 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21623131) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 12391 + ... + 14027.

It is an arithmetic number, because the mean of its divisors is an integer number (1120392).

Almost surely, 2^21623133 is an apocalyptic number.

It is an amenable number.

21623133 is a deficient number, since it is larger than the sum of its proper divisors (14229411).

21623133 is a wasteful number, since it uses less digits than its factorization.

21623133 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1701.

The product of its digits is 648, while the sum is 21.

The square root of 21623133 is about 4650.0680640180. The cubic root of 21623133 is about 278.5947147999.

Adding to 21623133 its reverse (33132612), we get a palindrome (54755745).

The spelling of 21623133 in words is "twenty-one million, six hundred twenty-three thousand, one hundred thirty-three".