21592191 has 4 divisors (see below), whose sum is σ = 28789592. Its totient is φ = 14394792.

The previous prime is 21592187. The next prime is 21592217. The reversal of 21592191 is 19129512.

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

It is not a de Polignac number, because 21592191 - 2² = 21592187 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 (21592111) 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, 3598696 + ... + 3598701.

It is an arithmetic number, because the mean of its divisors is an integer number (7197398).

Almost surely, 2^21592191 is an apocalyptic number.

21592191 is a deficient number, since it is larger than the sum of its proper divisors (7197401).

21592191 is an equidigital number, since it uses as much as digits as its factorization.

21592191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7197400.

The product of its digits is 1620, while the sum is 30.

The square root of 21592191 is about 4646.7398248665. The cubic root of 21592191 is about 278.4617647056.

The spelling of 21592191 in words is "twenty-one million, five hundred ninety-two thousand, one hundred ninety-one".