21453529 has 2 divisors, whose sum is σ = 21453530. Its totient is φ = 21453528.

The previous prime is 21453493. The next prime is 21453559. The reversal of 21453529 is 92535412.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17139600 + 4313929 = 4140^2 + 2077^2 .

It is a cyclic number.

It is not a de Polignac number, because 21453529 - 2⁷ = 21453401 is a prime.

It is a plaindrome in base 11.

It is a self number, because there is not a number n which added to its sum of digits gives 21453529.

It is not a weakly prime, because it can be changed into another prime (21453559) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10726764 + 10726765.

It is an arithmetic number, because the mean of its divisors is an integer number (10726765).

Almost surely, 2^21453529 is an apocalyptic number.

It is an amenable number.

21453529 is a deficient number, since it is larger than the sum of its proper divisors (1).

21453529 is an equidigital number, since it uses as much as digits as its factorization.

21453529 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10800, while the sum is 31.

The square root of 21453529 is about 4631.7954402154. The cubic root of 21453529 is about 277.8644034480.

The spelling of 21453529 in words is "twenty-one million, four hundred fifty-three thousand, five hundred twenty-nine".