21240467 has 4 divisors (see below), whose sum is σ = 21255336. Its totient is φ = 21225600.

The previous prime is 21240433. The next prime is 21240511. The reversal of 21240467 is 76404212.

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

It is a cyclic number.

It is not a de Polignac number, because 21240467 - 2⁶ = 21240403 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21245467) 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, 5033 + ... + 8234.

It is an arithmetic number, because the mean of its divisors is an integer number (5313834).

Almost surely, 2^21240467 is an apocalyptic number.

21240467 is a deficient number, since it is larger than the sum of its proper divisors (14869).

21240467 is a wasteful number, since it uses less digits than its factorization.

21240467 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14868.

The product of its (nonzero) digits is 2688, while the sum is 26.

The square root of 21240467 is about 4608.7381136272. The cubic root of 21240467 is about 276.9414873780.

Adding to 21240467 its reverse (76404212), we get a palindrome (97644679).

The spelling of 21240467 in words is "twenty-one million, two hundred forty thousand, four hundred sixty-seven".