10661511551 has 4 divisors (see below), whose sum is σ = 10708068600. Its totient is φ = 10614954504.

The previous prime is 10661511521. The next prime is 10661511577. The reversal of 10661511551 is 15511516601.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-10661511551 is a prime.

It is a super-2 number, since 2×10661511551² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (10661511521) 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, 23278181 + ... + 23278638.

It is an arithmetic number, because the mean of its divisors is an integer number (2677017150).

Almost surely, 2^10661511551 is an apocalyptic number.

10661511551 is a deficient number, since it is larger than the sum of its proper divisors (46557049).

10661511551 is an equidigital number, since it uses as much as digits as its factorization.

10661511551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46557048.

The product of its (nonzero) digits is 4500, while the sum is 32.

The spelling of 10661511551 in words is "ten billion, six hundred sixty-one million, five hundred eleven thousand, five hundred fifty-one".