21531735 has 12 divisors (see below), whose sum is σ = 37321752. Its totient is φ = 11483568.

The previous prime is 21531733. The next prime is 21531737. The reversal of 21531735 is 53713512.

It is an interprime number because it is at equal distance from previous prime (21531733) and next prime (21531737).

It is not a de Polignac number, because 21531735 - 2¹ = 21531733 is a prime.

It is a super-2 number, since 2×21531735² = 927231224220450, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21531699 and 21531708.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21531733) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 239197 + ... + 239286.

It is an arithmetic number, because the mean of its divisors is an integer number (3110146).

Almost surely, 2^21531735 is an apocalyptic number.

21531735 is a deficient number, since it is larger than the sum of its proper divisors (15790017).

21531735 is a wasteful number, since it uses less digits than its factorization.

21531735 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 478494 (or 478491 counting only the distinct ones).

The product of its digits is 3150, while the sum is 27.

The square root of 21531735 is about 4640.2300589518. The cubic root of 21531735 is about 278.2016333036.

The spelling of 21531735 in words is "twenty-one million, five hundred thirty-one thousand, seven hundred thirty-five".