21011465 has 4 divisors (see below), whose sum is σ = 25213764. Its totient is φ = 16809168.

The previous prime is 21011453. The next prime is 21011503. The reversal of 21011465 is 56411012.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 11641744 + 9369721 = 3412^2 + 3061^2 .

It is a cyclic number.

It is not a de Polignac number, because 21011465 - 2¹⁰ = 21010441 is a prime.

It is a super-2 number, since 2×21011465² = 882963322892450, which contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2101142 + ... + 2101151.

It is an arithmetic number, because the mean of its divisors is an integer number (6303441).

Almost surely, 2^21011465 is an apocalyptic number.

It is an amenable number.

21011465 is a deficient number, since it is larger than the sum of its proper divisors (4202299).

21011465 is an equidigital number, since it uses as much as digits as its factorization.

21011465 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4202298.

The product of its (nonzero) digits is 240, while the sum is 20.

The square root of 21011465 is about 4583.8264583206. The cubic root of 21011465 is about 275.9426165446.

Adding to 21011465 its reverse (56411012), we get a palindrome (77422477).

The spelling of 21011465 in words is "twenty-one million, eleven thousand, four hundred sixty-five".