21354787 has 4 divisors (see below), whose sum is σ = 22283280. Its totient is φ = 20426296.

The previous prime is 21354721. The next prime is 21354797. The reversal of 21354787 is 78745312.

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

It is a cyclic number.

It is not a de Polignac number, because 21354787 - 2⁷ = 21354659 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21354797) 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, 464212 + ... + 464257.

It is an arithmetic number, because the mean of its divisors is an integer number (5570820).

Almost surely, 2^21354787 is an apocalyptic number.

21354787 is a deficient number, since it is larger than the sum of its proper divisors (928493).

21354787 is an equidigital number, since it uses as much as digits as its factorization.

21354787 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 928492.

The product of its digits is 47040, while the sum is 37.

The square root of 21354787 is about 4621.1239974707. The cubic root of 21354787 is about 277.4374482283.

The spelling of 21354787 in words is "twenty-one million, three hundred fifty-four thousand, seven hundred eighty-seven".