21080567 has 4 divisors (see below), whose sum is σ = 21114096. Its totient is φ = 21047040.

The previous prime is 21080537. The next prime is 21080573. The reversal of 21080567 is 76508012.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21080567 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21080537) 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, 15803 + ... + 17084.

It is an arithmetic number, because the mean of its divisors is an integer number (5278524).

Almost surely, 2^21080567 is an apocalyptic number.

21080567 is a deficient number, since it is larger than the sum of its proper divisors (33529).

21080567 is an equidigital number, since it uses as much as digits as its factorization.

21080567 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33528.

The product of its (nonzero) digits is 3360, while the sum is 29.

The square root of 21080567 is about 4591.3578601542. The cubic root of 21080567 is about 276.2447900030.

Adding to 21080567 its reverse (76508012), we get a palindrome (97588579).

The spelling of 21080567 in words is "twenty-one million, eighty thousand, five hundred sixty-seven".