21369017 has 16 divisors (see below), whose sum is σ = 23712912. Its totient is φ = 19169280.

The previous prime is 21369011. The next prime is 21369031. The reversal of 21369017 is 71096312.

It can be written as a sum of positive squares in 8 ways, for example, as 9369721 + 11999296 = 3061^2 + 3464^2 .

It is a cyclic number.

It is not a de Polignac number, because 21369017 - 2⁶ = 21368953 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21369011) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 33017 + ... + 33657.

It is an arithmetic number, because the mean of its divisors is an integer number (1482057).

Almost surely, 2^21369017 is an apocalyptic number.

It is an amenable number.

21369017 is a deficient number, since it is larger than the sum of its proper divisors (2343895).

21369017 is a wasteful number, since it uses less digits than its factorization.

21369017 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 748.

The product of its (nonzero) digits is 2268, while the sum is 29.

The square root of 21369017 is about 4622.6634097671. The cubic root of 21369017 is about 277.4990590559.

The spelling of 21369017 in words is "twenty-one million, three hundred sixty-nine thousand, seventeen".