21060531 has 24 divisors (see below), whose sum is σ = 32448000. Its totient is φ = 13124592.

The previous prime is 21060509. The next prime is 21060539. The reversal of 21060531 is 13506012.

It is not a de Polignac number, because 21060531 - 2¹¹ = 21058483 is a prime.

It is a super-2 number, since 2×21060531² = 887091932003922, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21060539) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 12730 + ... + 14288.

It is an arithmetic number, because the mean of its divisors is an integer number (1352000).

Almost surely, 2^21060531 is an apocalyptic number.

21060531 is a deficient number, since it is larger than the sum of its proper divisors (11387469).

21060531 is a wasteful number, since it uses less digits than its factorization.

21060531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1663 (or 1660 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 18.

The square root of 21060531 is about 4589.1754161287. The cubic root of 21060531 is about 276.1572434161.

Adding to 21060531 its reverse (13506012), we get a palindrome (34566543).

The spelling of 21060531 in words is "twenty-one million, sixty thousand, five hundred thirty-one".