21420527 has 4 divisors (see below), whose sum is σ = 22680576. Its totient is φ = 20160480.

The previous prime is 21420499. The next prime is 21420541. The reversal of 21420527 is 72502412.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21420527 - 2¹² = 21416431 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21420587) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 629999 + ... + 630032.

It is an arithmetic number, because the mean of its divisors is an integer number (5670144).

Almost surely, 2^21420527 is an apocalyptic number.

21420527 is a deficient number, since it is larger than the sum of its proper divisors (1260049).

21420527 is a wasteful number, since it uses less digits than its factorization.

21420527 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1260048.

The product of its (nonzero) digits is 1120, while the sum is 23.

The square root of 21420527 is about 4628.2315197060. The cubic root of 21420527 is about 277.7218505657.

Adding to 21420527 its reverse (72502412), we get a palindrome (93922939).

The spelling of 21420527 in words is "twenty-one million, four hundred twenty thousand, five hundred twenty-seven".