21497111 has 8 divisors (see below), whose sum is σ = 23038944. Its totient is φ = 20005920.

The previous prime is 21497101. The next prime is 21497123. The reversal of 21497111 is 11179412.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21497111 - 2¹⁴ = 21480727 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 (21497101) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11780 + ... + 13481.

It is an arithmetic number, because the mean of its divisors is an integer number (2879868).

Almost surely, 2^21497111 is an apocalyptic number.

21497111 is a deficient number, since it is larger than the sum of its proper divisors (1541833).

21497111 is a wasteful number, since it uses less digits than its factorization.

21497111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25321.

The product of its digits is 504, while the sum is 26.

The square root of 21497111 is about 4636.4977084002. The cubic root of 21497111 is about 278.0524330478.

The spelling of 21497111 in words is "twenty-one million, four hundred ninety-seven thousand, one hundred eleven".