21039527 has 2 divisors, whose sum is σ = 21039528. Its totient is φ = 21039526.

The previous prime is 21039521. The next prime is 21039559. The reversal of 21039527 is 72593012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21039527 - 2¹² = 21035431 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21039527.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21039521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10519763 + 10519764.

It is an arithmetic number, because the mean of its divisors is an integer number (10519764).

Almost surely, 2^21039527 is an apocalyptic number.

21039527 is a deficient number, since it is larger than the sum of its proper divisors (1).

21039527 is an equidigital number, since it uses as much as digits as its factorization.

21039527 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3780, while the sum is 29.

The square root of 21039527 is about 4586.8864167319. The cubic root of 21039527 is about 276.0654075536.

The spelling of 21039527 in words is "twenty-one million, thirty-nine thousand, five hundred twenty-seven".