21354293 has 2 divisors, whose sum is σ = 21354294. Its totient is φ = 21354292.

The previous prime is 21354251. The next prime is 21354301. The reversal of 21354293 is 39245312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17123044 + 4231249 = 4138^2 + 2057^2 .

It is a cyclic number.

It is not a de Polignac number, because 21354293 - 2²⁴ = 4577077 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a plaindrome in base 13.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21351293) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10677146 + 10677147.

It is an arithmetic number, because the mean of its divisors is an integer number (10677147).

Almost surely, 2^21354293 is an apocalyptic number.

It is an amenable number.

21354293 is a deficient number, since it is larger than the sum of its proper divisors (1).

21354293 is an equidigital number, since it uses as much as digits as its factorization.

21354293 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6480, while the sum is 29.

The square root of 21354293 is about 4621.0705469620. The cubic root of 21354293 is about 277.4353088929.

It can be divided in two parts, 21 and 354293, that multiplied together give a triangular number (7440153 = T₃₈₅₇).

The spelling of 21354293 in words is "twenty-one million, three hundred fifty-four thousand, two hundred ninety-three".