21933645 has 16 divisors (see below), whose sum is σ = 35206080. Its totient is φ = 11660544.

The previous prime is 21933643. The next prime is 21933649. The reversal of 21933645 is 54633912.

It is not a de Polignac number, because 21933645 - 2¹ = 21933643 is a prime.

It is a super-3 number, since 3×21933645³ (a number of 23 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21933641) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2886 + ... + 7224.

It is an arithmetic number, because the mean of its divisors is an integer number (2200380).

Almost surely, 2^21933645 is an apocalyptic number.

It is an amenable number.

21933645 is a deficient number, since it is larger than the sum of its proper divisors (13272435).

21933645 is a wasteful number, since it uses less digits than its factorization.

21933645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4684.

The product of its digits is 19440, while the sum is 33.

The square root of 21933645 is about 4683.3369513628. The cubic root of 21933645 is about 279.9219382731.

It can be divided in two parts, 21933 and 645, that added together give a triangular number (22578 = T₂₁₂).

The spelling of 21933645 in words is "twenty-one million, nine hundred thirty-three thousand, six hundred forty-five".