21180529 has 2 divisors, whose sum is σ = 21180530. Its totient is φ = 21180528.

The previous prime is 21180491. The next prime is 21180571. The reversal of 21180529 is 92508112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13890529 + 7290000 = 3727^2 + 2700^2 .

It is a cyclic number.

It is not a de Polignac number, because 21180529 - 2⁹ = 21180017 is a prime.

It is a super-2 number, since 2×21180529² = 897229617439682, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21180497 and 21180506.

It is not a weakly prime, because it can be changed into another prime (21181529) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10590264 + 10590265.

It is an arithmetic number, because the mean of its divisors is an integer number (10590265).

Almost surely, 2^21180529 is an apocalyptic number.

It is an amenable number.

21180529 is a deficient number, since it is larger than the sum of its proper divisors (1).

21180529 is an equidigital number, since it uses as much as digits as its factorization.

21180529 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1440, while the sum is 28.

The square root of 21180529 is about 4602.2308720880. The cubic root of 21180529 is about 276.6807436266.

The spelling of 21180529 in words is "twenty-one million, one hundred eighty thousand, five hundred twenty-nine".