21502132 has 6 divisors (see below), whose sum is σ = 37628738. Its totient is φ = 10751064.

The previous prime is 21502123. The next prime is 21502157. The reversal of 21502132 is 23120512.

It can be written as a sum of positive squares in only one way, i.e., 15713296 + 5788836 = 3964^2 + 2406^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2687763 + ... + 2687770.

Almost surely, 2^21502132 is an apocalyptic number.

It is an amenable number.

21502132 is a deficient number, since it is larger than the sum of its proper divisors (16126606).

21502132 is a wasteful number, since it uses less digits than its factorization.

21502132 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5375537 (or 5375535 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 16.

The square root of 21502132 is about 4637.0391415212. The cubic root of 21502132 is about 278.0740792524.

Adding to 21502132 its reverse (23120512), we get a palindrome (44622644).

The spelling of 21502132 in words is "twenty-one million, five hundred two thousand, one hundred thirty-two".