21849497 has 4 divisors (see below), whose sum is σ = 21920976. Its totient is φ = 21778020.

The previous prime is 21849491. The next prime is 21849511. The reversal of 21849497 is 79494812.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21849497 - 2¹⁰ = 21848473 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21849491) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 35279 + ... + 35892.

It is an arithmetic number, because the mean of its divisors is an integer number (5480244).

Almost surely, 2^21849497 is an apocalyptic number.

It is an amenable number.

21849497 is a deficient number, since it is larger than the sum of its proper divisors (71479).

21849497 is an equidigital number, since it uses as much as digits as its factorization.

21849497 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71478.

The product of its digits is 145152, while the sum is 44.

The square root of 21849497 is about 4674.3445529828. The cubic root of 21849497 is about 279.5635078308.

The spelling of 21849497 in words is "twenty-one million, eight hundred forty-nine thousand, four hundred ninety-seven".