21055773 has 8 divisors (see below), whose sum is σ = 28352736. Its totient is φ = 13898000.

The previous prime is 21055763. The next prime is 21055799. The reversal of 21055773 is 37755012.

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 21055773 - 2⁹ = 21055261 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21055773.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21055703) 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, 34443 + ... + 35048.

It is an arithmetic number, because the mean of its divisors is an integer number (3544092).

Almost surely, 2^21055773 is an apocalyptic number.

It is an amenable number.

21055773 is a deficient number, since it is larger than the sum of its proper divisors (7296963).

21055773 is a wasteful number, since it uses less digits than its factorization.

21055773 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69595.

The product of its (nonzero) digits is 7350, while the sum is 30.

The square root of 21055773 is about 4588.6569930645. The cubic root of 21055773 is about 276.1364453472.

The spelling of 21055773 in words is "twenty-one million, fifty-five thousand, seven hundred seventy-three".