21353784693 has 8 divisors (see below), whose sum is σ = 28472615808. Its totient is φ = 14235405024.

The previous prime is 21353784679. The next prime is 21353784713. The reversal of 21353784693 is 39648735312.

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

It is not a de Polignac number, because 21353784693 - 2⁸ = 21353784437 is a prime.

It is a super-2 number, since 2×21353784693² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21353782693) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19780 + ... + 207602.

It is an arithmetic number, because the mean of its divisors is an integer number (3559076976).

Almost surely, 2^21353784693 is an apocalyptic number.

It is an amenable number.

21353784693 is a deficient number, since it is larger than the sum of its proper divisors (7118831115).

21353784693 is a wasteful number, since it uses less digits than its factorization.

21353784693 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 225723.

The product of its digits is 3265920, while the sum is 51.

The spelling of 21353784693 in words is "twenty-one billion, three hundred fifty-three million, seven hundred eighty-four thousand, six hundred ninety-three".