1866129249601 has 4 divisors (see below), whose sum is σ = 1930478534100. Its totient is φ = 1801779965104.

The previous prime is 1866129249581. The next prime is 1866129249629. The reversal of 1866129249601 is 1069429216681.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 304978958001 + 1561150291600 = 552249^2 + 1249460^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1866129249601 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1866129259601) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 32174642206 + ... + 32174642263.

It is an arithmetic number, because the mean of its divisors is an integer number (482619633525).

Almost surely, 2^{1866129249601} is an apocalyptic number.

It is an amenable number.

1866129249601 is a deficient number, since it is larger than the sum of its proper divisors (64349284499).

1866129249601 is an equidigital number, since it uses as much as digits as its factorization.

1866129249601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64349284498.

The product of its (nonzero) digits is 2239488, while the sum is 55.

The spelling of 1866129249601 in words is "one trillion, eight hundred sixty-six billion, one hundred twenty-nine million, two hundred forty-nine thousand, six hundred one".