1666057256461 has 8 divisors (see below), whose sum is σ = 1796395610240. Its totient is φ = 1536030346032.

The previous prime is 1666057256417. The next prime is 1666057256491. The reversal of 1666057256461 is 1646527506661.

It is a happy number.

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

It is not a de Polignac number, because 1666057256461 - 2²¹ = 1666055159309 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 (1666057256401) 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, 77849721 + ... + 77871118.

It is an arithmetic number, because the mean of its divisors is an integer number (224549451280).

Almost surely, 2^{1666057256461} is an apocalyptic number.

It is an amenable number.

1666057256461 is a deficient number, since it is larger than the sum of its proper divisors (130338353779).

1666057256461 is a wasteful number, since it uses less digits than its factorization.

1666057256461 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 155721675.

The product of its (nonzero) digits is 10886400, while the sum is 55.

The spelling of 1666057256461 in words is "one trillion, six hundred sixty-six billion, fifty-seven million, two hundred fifty-six thousand, four hundred sixty-one".