21497349 has 4 divisors (see below), whose sum is σ = 28663136. Its totient is φ = 14331564.

The previous prime is 21497339. The next prime is 21497351. The reversal of 21497349 is 94379412.

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 not a de Polignac number, because 21497349 - 2⁵ = 21497317 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 (21497339) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3582889 + ... + 3582894.

It is an arithmetic number, because the mean of its divisors is an integer number (7165784).

Almost surely, 2^21497349 is an apocalyptic number.

It is an amenable number.

21497349 is a deficient number, since it is larger than the sum of its proper divisors (7165787).

21497349 is an equidigital number, since it uses as much as digits as its factorization.

21497349 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7165786.

The product of its digits is 54432, while the sum is 39.

The square root of 21497349 is about 4636.5233742536. The cubic root of 21497349 is about 278.0534591738.

The spelling of 21497349 in words is "twenty-one million, four hundred ninety-seven thousand, three hundred forty-nine".