21554719 has 4 divisors (see below), whose sum is σ = 21615120. Its totient is φ = 21494320.

The previous prime is 21554711. The next prime is 21554723. The reversal of 21554719 is 91745512.

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 21554719 - 2³ = 21554711 is a prime.

It is a super-2 number, since 2×21554719² = 929211822337922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21554711) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 29662 + ... + 30379.

It is an arithmetic number, because the mean of its divisors is an integer number (5403780).

Almost surely, 2^21554719 is an apocalyptic number.

21554719 is a deficient number, since it is larger than the sum of its proper divisors (60401).

21554719 is an equidigital number, since it uses as much as digits as its factorization.

21554719 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60400.

The product of its digits is 12600, while the sum is 34.

The square root of 21554719 is about 4642.7059997377. The cubic root of 21554719 is about 278.3005866630.

The spelling of 21554719 in words is "twenty-one million, five hundred fifty-four thousand, seven hundred nineteen".