21600161731 has 8 divisors (see below), whose sum is σ = 21751163280. Its totient is φ = 21449684448.

The previous prime is 21600161729. The next prime is 21600161773. The reversal of 21600161731 is 13716100612.

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 21600161731 - 2¹ = 21600161729 is a prime.

It is a super-2 number, since 2×21600161731² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21600161731.

It is not an unprimeable number, because it can be changed into a prime (21600161711) 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, 48196 + ... + 213361.

It is an arithmetic number, because the mean of its divisors is an integer number (2718895410).

Almost surely, 2^21600161731 is an apocalyptic number.

21600161731 is a deficient number, since it is larger than the sum of its proper divisors (151001549).

21600161731 is a wasteful number, since it uses less digits than its factorization.

21600161731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 262133.

The product of its (nonzero) digits is 1512, while the sum is 28.

The spelling of 21600161731 in words is "twenty-one billion, six hundred million, one hundred sixty-one thousand, seven hundred thirty-one".