21531652 has 6 divisors (see below), whose sum is σ = 37680398. Its totient is φ = 10765824.

The previous prime is 21531649. The next prime is 21531667. The reversal of 21531652 is 25613512.

It can be written as a sum of positive squares in only one way, i.e., 16451136 + 5080516 = 4056^2 + 2254^2 .

It is a super-2 number, since 2×21531652² = 927224075698208, which contains 22 as substring.

It is a plaindrome in base 9.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 2691453 + ... + 2691460.

Almost surely, 2^21531652 is an apocalyptic number.

It is an amenable number.

21531652 is a deficient number, since it is larger than the sum of its proper divisors (16148746).

21531652 is a wasteful number, since it uses less digits than its factorization.

21531652 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5382917 (or 5382915 counting only the distinct ones).

The product of its digits is 1800, while the sum is 25.

The square root of 21531652 is about 4640.2211154211. The cubic root of 21531652 is about 278.2012758349.

The spelling of 21531652 in words is "twenty-one million, five hundred thirty-one thousand, six hundred fifty-two".