21535093 has 2 divisors, whose sum is σ = 21535094. Its totient is φ = 21535092.

The previous prime is 21535091. The next prime is 21535121. The reversal of 21535093 is 39053512.

It is an a-pointer prime, because the next prime (21535121) can be obtained adding 21535093 to its sum of digits (28).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13593969 + 7941124 = 3687^2 + 2818^2 .

It is a cyclic number.

It is not a de Polignac number, because 21535093 - 2¹ = 21535091 is a prime.

It is a super-3 number, since 3×21535093³ (a number of 23 digits) contains 333 as substring.

Together with 21535091, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21535091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10767546 + 10767547.

It is an arithmetic number, because the mean of its divisors is an integer number (10767547).

Almost surely, 2^21535093 is an apocalyptic number.

It is an amenable number.

21535093 is a deficient number, since it is larger than the sum of its proper divisors (1).

21535093 is an equidigital number, since it uses as much as digits as its factorization.

21535093 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4050, while the sum is 28.

The square root of 21535093 is about 4640.5918803532. The cubic root of 21535093 is about 278.2160949424.

It can be divided in two parts, 2153509 and 3, that added together give a palindrome (2153512).

The spelling of 21535093 in words is "twenty-one million, five hundred thirty-five thousand, ninety-three".