21534365 has 8 divisors (see below), whose sum is σ = 25866168. Its totient is φ = 17210880.

The previous prime is 21534349. The next prime is 21534397. The reversal of 21534365 is 56343512.

It can be written as a sum of positive squares in 4 ways, for example, as 5067001 + 16467364 = 2251^2 + 4058^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21534365 - 2⁴ = 21534349 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8885 + ... + 11045.

It is an arithmetic number, because the mean of its divisors is an integer number (3233271).

Almost surely, 2^21534365 is an apocalyptic number.

It is an amenable number.

21534365 is a deficient number, since it is larger than the sum of its proper divisors (4331803).

21534365 is a wasteful number, since it uses less digits than its factorization.

21534365 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4159.

The product of its digits is 10800, while the sum is 29.

The square root of 21534365 is about 4640.5134414200. The cubic root of 21534365 is about 278.2129598488.

Adding to 21534365 its reverse (56343512), we get a palindrome (77877877).

The spelling of 21534365 in words is "twenty-one million, five hundred thirty-four thousand, three hundred sixty-five".