21053527 has 4 divisors (see below), whose sum is σ = 22967496. Its totient is φ = 19139560.

The previous prime is 21053521. The next prime is 21053537. The reversal of 21053527 is 72535012.

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

It is not a de Polignac number, because 21053527 - 2⁷ = 21053399 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 (21053521) 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, 956968 + ... + 956989.

It is an arithmetic number, because the mean of its divisors is an integer number (5741874).

Almost surely, 2^21053527 is an apocalyptic number.

21053527 is a deficient number, since it is larger than the sum of its proper divisors (1913969).

21053527 is a wasteful number, since it uses less digits than its factorization.

21053527 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1913968.

The product of its (nonzero) digits is 2100, while the sum is 25.

The square root of 21053527 is about 4588.4122526207. The cubic root of 21053527 is about 276.1266265909.

Adding to 21053527 its reverse (72535012), we get a palindrome (93588539).

The spelling of 21053527 in words is "twenty-one million, fifty-three thousand, five hundred twenty-seven".