1011051111661 has 4 divisors (see below), whose sum is σ = 1011059732032. Its totient is φ = 1011042491292.

The previous prime is 1011051111533. The next prime is 1011051111691. The reversal of 1011051111661 is 1661111501101.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1011051111661 - 2⁷ = 1011051111533 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 (1011051111691) 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, 4131795 + ... + 4369648.

It is an arithmetic number, because the mean of its divisors is an integer number (252764933008).

Almost surely, 2^{1011051111661} is an apocalyptic number.

It is an amenable number.

1011051111661 is a deficient number, since it is larger than the sum of its proper divisors (8620371).

1011051111661 is an equidigital number, since it uses as much as digits as its factorization.

1011051111661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8620370.

The product of its (nonzero) digits is 180, while the sum is 25.

Adding to 1011051111661 its reverse (1661111501101), we get a palindrome (2672162612762).

The spelling of 1011051111661 in words is "one trillion, eleven billion, fifty-one million, one hundred eleven thousand, six hundred sixty-one".