21456091 has 8 divisors (see below), whose sum is σ = 22865760. Its totient is φ = 20062848.

The previous prime is 21456089. The next prime is 21456103. The reversal of 21456091 is 19065412.

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 21456091 - 2¹ = 21456089 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21456191) 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, 1351 + ... + 6688.

It is an arithmetic number, because the mean of its divisors is an integer number (2858220).

Almost surely, 2^21456091 is an apocalyptic number.

21456091 is a deficient number, since it is larger than the sum of its proper divisors (1409669).

21456091 is a wasteful number, since it uses less digits than its factorization.

21456091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8213.

The product of its (nonzero) digits is 2160, while the sum is 28.

The square root of 21456091 is about 4632.0719985769. The cubic root of 21456091 is about 277.8754639478.

The spelling of 21456091 in words is "twenty-one million, four hundred fifty-six thousand, ninety-one".