21738532 has 6 divisors (see below), whose sum is σ = 38042438. Its totient is φ = 10869264.

The previous prime is 21738503. The next prime is 21738539. The reversal of 21738532 is 23583712.

It can be written as a sum of positive squares in only one way, i.e., 13351716 + 8386816 = 3654^2 + 2896^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21738494 and 21738503.

It is not an unprimeable number, because it can be changed into a prime (21738539) 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 as a sum of consecutive naturals, namely, 2717313 + ... + 2717320.

Almost surely, 2^21738532 is an apocalyptic number.

It is an amenable number.

21738532 is a deficient number, since it is larger than the sum of its proper divisors (16303906).

21738532 is a wasteful number, since it uses less digits than its factorization.

21738532 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5434637 (or 5434635 counting only the distinct ones).

The product of its digits is 10080, while the sum is 31.

The square root of 21738532 is about 4662.4598657790. The cubic root of 21738532 is about 279.0894400281.

The spelling of 21738532 in words is "twenty-one million, seven hundred thirty-eight thousand, five hundred thirty-two".