21455033 has 2 divisors, whose sum is σ = 21455034. Its totient is φ = 21455032.

The previous prime is 21455023. The next prime is 21455039. The reversal of 21455033 is 33055412.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21132409 + 322624 = 4597^2 + 568^2 .

It is a cyclic number.

It is not a de Polignac number, because 21455033 - 2⁸ = 21454777 is a prime.

It is not a weakly prime, because it can be changed into another prime (21455039) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10727516 + 10727517.

It is an arithmetic number, because the mean of its divisors is an integer number (10727517).

Almost surely, 2^21455033 is an apocalyptic number.

It is an amenable number.

21455033 is a deficient number, since it is larger than the sum of its proper divisors (1).

21455033 is an equidigital number, since it uses as much as digits as its factorization.

21455033 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1800, while the sum is 23.

The square root of 21455033 is about 4631.9577934174. The cubic root of 21455033 is about 277.8708965257.

The spelling of 21455033 in words is "twenty-one million, four hundred fifty-five thousand, thirty-three".