21606347774 has 8 divisors (see below), whose sum is σ = 35355841848. Its totient is φ = 9821067160.

The previous prime is 21606347773. The next prime is 21606347779. The reversal of 21606347774 is 47774360612.

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

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21606347771) 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, 491053337 + ... + 491053380.

It is an arithmetic number, because the mean of its divisors is an integer number (4419480231).

Almost surely, 2^21606347774 is an apocalyptic number.

21606347774 is a deficient number, since it is larger than the sum of its proper divisors (13749494074).

21606347774 is a wasteful number, since it uses less digits than its factorization.

21606347774 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 982106730.

The product of its (nonzero) digits is 1185408, while the sum is 47.

The spelling of 21606347774 in words is "twenty-one billion, six hundred six million, three hundred forty-seven thousand, seven hundred seventy-four".