21440527 has 2 divisors, whose sum is σ = 21440528. Its totient is φ = 21440526.

The previous prime is 21440491. The next prime is 21440537. The reversal of 21440527 is 72504412.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21440527 - 2⁷ = 21440399 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21440537) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10720263 + 10720264.

It is an arithmetic number, because the mean of its divisors is an integer number (10720264).

Almost surely, 2^21440527 is an apocalyptic number.

21440527 is a deficient number, since it is larger than the sum of its proper divisors (1).

21440527 is an equidigital number, since it uses as much as digits as its factorization.

21440527 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2240, while the sum is 25.

The square root of 21440527 is about 4630.3916680989. The cubic root of 21440527 is about 277.8082584804.

Adding to 21440527 its reverse (72504412), we get a palindrome (93944939).

The spelling of 21440527 in words is "twenty-one million, four hundred forty thousand, five hundred twenty-seven".