21014531 has 4 divisors (see below), whose sum is σ = 21739200. Its totient is φ = 20289864.

The previous prime is 21014527. The next prime is 21014579. The reversal of 21014531 is 13541012.

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 21014531 - 2² = 21014527 is a prime.

It is a super-2 number, since 2×21014531² = 883221026299922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21014501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 362291 + ... + 362348.

It is an arithmetic number, because the mean of its divisors is an integer number (5434800).

Almost surely, 2^21014531 is an apocalyptic number.

21014531 is a deficient number, since it is larger than the sum of its proper divisors (724669).

21014531 is an equidigital number, since it uses as much as digits as its factorization.

21014531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 724668.

The product of its (nonzero) digits is 120, while the sum is 17.

The square root of 21014531 is about 4584.1608828661. The cubic root of 21014531 is about 275.9560377714.

Adding to 21014531 its reverse (13541012), we get a palindrome (34555543).

It can be divided in two parts, 210 and 14531, that added together give a palindrome (14741).

The spelling of 21014531 in words is "twenty-one million, fourteen thousand, five hundred thirty-one".