21517067 has 12 divisors (see below), whose sum is σ = 25472160. Its totient is φ = 18054960.

The previous prime is 21517057. The next prime is 21517073. The reversal of 21517067 is 76071512.

It is not a de Polignac number, because 21517067 - 2⁴ = 21517051 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21517057) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5267 + ... + 8412.

It is an arithmetic number, because the mean of its divisors is an integer number (2122680).

Almost surely, 2^21517067 is an apocalyptic number.

21517067 is a deficient number, since it is larger than the sum of its proper divisors (3955093).

21517067 is a wasteful number, since it uses less digits than its factorization.

21517067 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13714 (or 13703 counting only the distinct ones).

The product of its (nonzero) digits is 2940, while the sum is 29.

The square root of 21517067 is about 4638.6492646028. The cubic root of 21517067 is about 278.1384461285.

Adding to 21517067 its reverse (76071512), we get a palindrome (97588579).

The spelling of 21517067 in words is "twenty-one million, five hundred seventeen thousand, sixty-seven".