21132017 has 4 divisors (see below), whose sum is σ = 21319140. Its totient is φ = 20944896.

The previous prime is 21132011. The next prime is 21132061. The reversal of 21132017 is 71023112.

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 6964321 + 14167696 = 2639^2 + 3764^2 .

It is a cyclic number.

It is not a de Polignac number, because 21132017 - 2¹⁸ = 20869873 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21131986 and 21132004.

It is not an unprimeable number, because it can be changed into a prime (21132011) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 93392 + ... + 93617.

It is an arithmetic number, because the mean of its divisors is an integer number (5329785).

Almost surely, 2^21132017 is an apocalyptic number.

It is an amenable number.

21132017 is a deficient number, since it is larger than the sum of its proper divisors (187123).

21132017 is a wasteful number, since it uses less digits than its factorization.

21132017 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 187122.

The product of its (nonzero) digits is 84, while the sum is 17.

The square root of 21132017 is about 4596.9573633002. The cubic root of 21132017 is about 276.4693451164.

Adding to 21132017 its reverse (71023112), we get a palindrome (92155129).

The spelling of 21132017 in words is "twenty-one million, one hundred thirty-two thousand, seventeen".