105661511651 has 4 divisors (see below), whose sum is σ = 108118756152. Its totient is φ = 103204267152.

The previous prime is 105661511639. The next prime is 105661511671. The reversal of 105661511651 is 156115166501.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 156115166501 = 7 ⋅22302166643.

It is a cyclic number.

It is not a de Polignac number, because 105661511651 - 2⁶ = 105661511587 is a prime.

It is a super-2 number, since 2×105661511651² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (105661511671) 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, 1228622186 + ... + 1228622271.

It is an arithmetic number, because the mean of its divisors is an integer number (27029689038).

Almost surely, 2^105661511651 is an apocalyptic number.

105661511651 is a deficient number, since it is larger than the sum of its proper divisors (2457244501).

105661511651 is an equidigital number, since it uses as much as digits as its factorization.

105661511651 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2457244500.

The product of its (nonzero) digits is 27000, while the sum is 38.

The spelling of 105661511651 in words is "one hundred five billion, six hundred sixty-one million, five hundred eleven thousand, six hundred fifty-one".