21666154148473 has 32 divisors (see below), whose sum is σ = 22698525915648. Its totient is φ = 20664560716800.

The previous prime is 21666154148459. The next prime is 21666154148477. The reversal of 21666154148473 is 37484145166612.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21666154148473 - 2⁹ = 21666154147961 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21666154148477) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 231684261 + ... + 231777757.

It is an arithmetic number, because the mean of its divisors is an integer number (709328934864).

Almost surely, 2^{21666154148473} is an apocalyptic number.

It is an amenable number.

21666154148473 is a deficient number, since it is larger than the sum of its proper divisors (1032371767175).

21666154148473 is a wasteful number, since it uses less digits than its factorization.

21666154148473 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 94353.

The product of its digits is 23224320, while the sum is 58.

The spelling of 21666154148473 in words is "twenty-one trillion, six hundred sixty-six billion, one hundred fifty-four million, one hundred forty-eight thousand, four hundred seventy-three".