21420773 has 8 divisors (see below), whose sum is σ = 23408256. Its totient is φ = 19440000.

The previous prime is 21420761. The next prime is 21420793. The reversal of 21420773 is 37702412.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21420773 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 (21420703) 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, 6965 + ... + 9557.

It is an arithmetic number, because the mean of its divisors is an integer number (2926032).

Almost surely, 2^21420773 is an apocalyptic number.

It is an amenable number.

21420773 is a deficient number, since it is larger than the sum of its proper divisors (1987483).

21420773 is a wasteful number, since it uses less digits than its factorization.

21420773 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3355.

The product of its (nonzero) digits is 2352, while the sum is 26.

The square root of 21420773 is about 4628.2580956554. The cubic root of 21420773 is about 277.7229137097.

The spelling of 21420773 in words is "twenty-one million, four hundred twenty thousand, seven hundred seventy-three".