21525071 has 2 divisors, whose sum is σ = 21525072. Its totient is φ = 21525070.

The previous prime is 21525061. The next prime is 21525089. The reversal of 21525071 is 17052512.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21525071 - 2¹⁴ = 21508687 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21525001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10762535 + 10762536.

It is an arithmetic number, because the mean of its divisors is an integer number (10762536).

Almost surely, 2^21525071 is an apocalyptic number.

21525071 is a deficient number, since it is larger than the sum of its proper divisors (1).

21525071 is an equidigital number, since it uses as much as digits as its factorization.

21525071 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 700, while the sum is 23.

The square root of 21525071 is about 4639.5119355380. The cubic root of 21525071 is about 278.1729295170.

Adding to 21525071 its reverse (17052512), we get a palindrome (38577583).

The spelling of 21525071 in words is "twenty-one million, five hundred twenty-five thousand, seventy-one".