20125536643666 has 8 divisors (see below), whose sum is σ = 30355091181324. Its totient is φ = 10007172916560.

The previous prime is 20125536643633. The next prime is 20125536643673. The reversal of 20125536643666 is 66634663552102.

It can be written as a sum of positive squares in 2 ways, for example, as 20034763992441 + 90772651225 = 4476021^2 + 301285^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 27797702185 + ... + 27797702908.

Almost surely, 2^{20125536643666} is an apocalyptic number.

20125536643666 is a deficient number, since it is larger than the sum of its proper divisors (10229554537658).

20125536643666 is a wasteful number, since it uses less digits than its factorization.

20125536643666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55595405276.

The product of its (nonzero) digits is 27993600, while the sum is 55.

The spelling of 20125536643666 in words is "twenty trillion, one hundred twenty-five billion, five hundred thirty-six million, six hundred forty-three thousand, six hundred sixty-six".