21541197 has 4 divisors (see below), whose sum is σ = 28721600. Its totient is φ = 14360796.

The previous prime is 21541183. The next prime is 21541211. The reversal of 21541197 is 79114512.

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 an interprime number because it is at equal distance from previous prime (21541183) and next prime (21541211).

It is not a de Polignac number, because 21541197 - 2¹¹ = 21539149 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 (21541127) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3590197 + ... + 3590202.

It is an arithmetic number, because the mean of its divisors is an integer number (7180400).

Almost surely, 2^21541197 is an apocalyptic number.

It is an amenable number.

21541197 is a deficient number, since it is larger than the sum of its proper divisors (7180403).

21541197 is an equidigital number, since it uses as much as digits as its factorization.

21541197 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7180402.

The product of its digits is 2520, while the sum is 30.

The square root of 21541197 is about 4641.2495084837. The cubic root of 21541197 is about 278.2423787174.

The spelling of 21541197 in words is "twenty-one million, five hundred forty-one thousand, one hundred ninety-seven".