21660354562423 has 8 divisors (see below), whose sum is σ = 21715359675968. Its totient is φ = 21605351685984.

The previous prime is 21660354562421. The next prime is 21660354562471. The reversal of 21660354562423 is 32426545306612.

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 21660354562423 - 2¹ = 21660354562421 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 (21660354562421) 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, 19766290 + ... + 20833312.

It is an arithmetic number, because the mean of its divisors is an integer number (2714419959496).

Almost surely, 2^{21660354562423} is an apocalyptic number.

21660354562423 is a deficient number, since it is larger than the sum of its proper divisors (55005113545).

21660354562423 is a wasteful number, since it uses less digits than its factorization.

21660354562423 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1118553.

The product of its (nonzero) digits is 6220800, while the sum is 49.

The spelling of 21660354562423 in words is "twenty-one trillion, six hundred sixty billion, three hundred fifty-four million, five hundred sixty-two thousand, four hundred twenty-three".