21163065 has 64 divisors (see below), whose sum is σ = 42964992. Its totient is φ = 8640000.

The previous prime is 21163061. The next prime is 21163099. The reversal of 21163065 is 56036112.

It is not a de Polignac number, because 21163065 - 2² = 21163061 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21163061) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 84190 + ... + 84440.

It is an arithmetic number, because the mean of its divisors is an integer number (671328).

Almost surely, 2^21163065 is an apocalyptic number.

It is an amenable number.

21163065 is an abundant number, since it is smaller than the sum of its proper divisors (21801927).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21163065 is a wasteful number, since it uses less digits than its factorization.

21163065 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 350.

The product of its (nonzero) digits is 1080, while the sum is 24.

The square root of 21163065 is about 4600.3331401106. Note that the first 3 decimals coincide. The cubic root of 21163065 is about 276.6046787787.

Adding to 21163065 its reverse (56036112), we get a palindrome (77199177).

The spelling of 21163065 in words is "twenty-one million, one hundred sixty-three thousand, sixty-five".