21140717 has 6 divisors (see below), whose sum is σ = 22892202. Its totient is φ = 19514352.

The previous prime is 21140701. The next prime is 21140719. The reversal of 21140717 is 71704112.

It can be written as a sum of positive squares in 3 ways, for example, as 2253001 + 18887716 = 1501^2 + 4346^2 .

It is not a de Polignac number, because 21140717 - 2⁴ = 21140701 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21140692 and 21140701.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21140719) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 62378 + ... + 62715.

It is an arithmetic number, because the mean of its divisors is an integer number (3815367).

Almost surely, 2^21140717 is an apocalyptic number.

It is an amenable number.

21140717 is a deficient number, since it is larger than the sum of its proper divisors (1751485).

21140717 is a wasteful number, since it uses less digits than its factorization.

21140717 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 125119 (or 125106 counting only the distinct ones).

The product of its (nonzero) digits is 392, while the sum is 23.

The square root of 21140717 is about 4597.9035440079. The cubic root of 21140717 is about 276.5072804966.

Adding to 21140717 its reverse (71704112), we get a palindrome (92844829).

The spelling of 21140717 in words is "twenty-one million, one hundred forty thousand, seven hundred seventeen".