1661056550101 has 8 divisors (see below), whose sum is σ = 1837176891704. Its totient is φ = 1491842888640.

The previous prime is 1661056550089. The next prime is 1661056550123. The reversal of 1661056550101 is 1010556501661.

It can be written as a sum of positive squares in 4 ways, for example, as 573728987601 + 1087327562500 = 757449^2 + 1042750^2 .

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

It is not a de Polignac number, because 1661056550101 - 2³¹ = 1658909066453 is a prime.

It is a super-2 number, since 2×1661056550101² (a number of 25 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (37).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1661056550401) 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, 1726669530 + ... + 1726670491.

It is an arithmetic number, because the mean of its divisors is an integer number (229647111463).

Almost surely, 2^{1661056550101} is an apocalyptic number.

It is an amenable number.

1661056550101 is a deficient number, since it is larger than the sum of its proper divisors (176120341603).

1661056550101 is a wasteful number, since it uses less digits than its factorization.

1661056550101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3453340071.

The product of its (nonzero) digits is 27000, while the sum is 37.

The spelling of 1661056550101 in words is "one trillion, six hundred sixty-one billion, fifty-six million, five hundred fifty thousand, one hundred one".