1551661110101 has 8 divisors (see below), whose sum is σ = 1555083634104. Its totient is φ = 1548238832320.

The previous prime is 1551661110071. The next prime is 1551661110191. The reversal of 1551661110101 is 1010111661551.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 17902707601 + 1533758402500 = 133801^2 + 1238450^2 .

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1551661110101 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 (1551661110191) 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, 19069235 + ... + 19150431.

It is an arithmetic number, because the mean of its divisors is an integer number (194385454263).

Almost surely, 2^{1551661110101} is an apocalyptic number.

It is an amenable number.

1551661110101 is a deficient number, since it is larger than the sum of its proper divisors (3422524003).

1551661110101 is an equidigital number, since it uses as much as digits as its factorization.

1551661110101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 123111.

The product of its (nonzero) digits is 900, while the sum is 29.

Adding to 1551661110101 its reverse (1010111661551), we get a palindrome (2561772771652).

The spelling of 1551661110101 in words is "one trillion, five hundred fifty-one billion, six hundred sixty-one million, one hundred ten thousand, one hundred one".