21619033 has 4 divisors (see below), whose sum is σ = 21628980. Its totient is φ = 21609088.

The previous prime is 21619027. The next prime is 21619043. The reversal of 21619033 is 33091612.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 11614464 + 10004569 = 3408^2 + 3163^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21619033 is a prime.

It is a Duffinian number.

It is a plaindrome in base 11.

It is a junction number, because it is equal to n+sod(n) for n = 21618989 and 21619007.

It is not an unprimeable number, because it can be changed into a prime (21619043) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 160 + ... + 6577.

It is an arithmetic number, because the mean of its divisors is an integer number (5407245).

Almost surely, 2^21619033 is an apocalyptic number.

It is an amenable number.

21619033 is a deficient number, since it is larger than the sum of its proper divisors (9947).

21619033 is an equidigital number, since it uses as much as digits as its factorization.

21619033 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9946.

The product of its (nonzero) digits is 972, while the sum is 25.

The square root of 21619033 is about 4649.6271893562. The cubic root of 21619033 is about 278.5771054101.

The spelling of 21619033 in words is "twenty-one million, six hundred nineteen thousand, thirty-three".