21360436 has 6 divisors (see below), whose sum is σ = 37380770. Its totient is φ = 10680216.

The previous prime is 21360407. The next prime is 21360439. The reversal of 21360436 is 63406312.

It can be written as a sum of positive squares in only one way, i.e., 18011536 + 3348900 = 4244^2 + 1830^2 .

It is a super-2 number, since 2×21360436² = 912536452220192, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21360436.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21360439) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2670051 + ... + 2670058.

Almost surely, 2^21360436 is an apocalyptic number.

It is an amenable number.

21360436 is a deficient number, since it is larger than the sum of its proper divisors (16020334).

21360436 is a wasteful number, since it uses less digits than its factorization.

21360436 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5340113 (or 5340111 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 25.

The square root of 21360436 is about 4621.7351719890. The cubic root of 21360436 is about 277.4619096597.

Adding to 21360436 its reverse (63406312), we get a palindrome (84766748).

The spelling of 21360436 in words is "twenty-one million, three hundred sixty thousand, four hundred thirty-six".