1266500661 has 8 divisors (see below), whose sum is σ = 1689150144. Its totient is φ = 844092480.

The previous prime is 1266500659. The next prime is 1266500687. The reversal of 1266500661 is 1660056621.

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

It is not a de Polignac number, because 1266500661 - 2¹ = 1266500659 is a prime.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1266507661) 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, 47700 + ... + 69341.

It is an arithmetic number, because the mean of its divisors is an integer number (211143768).

Almost surely, 2^1266500661 is an apocalyptic number.

It is an amenable number.

1266500661 is a deficient number, since it is larger than the sum of its proper divisors (422649483).

1266500661 is a wasteful number, since it uses less digits than its factorization.

1266500661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 120651.

The product of its (nonzero) digits is 12960, while the sum is 33.

The square root of 1266500661 is about 35587.9285854066. The cubic root of 1266500661 is about 1081.9365862341.

The spelling of 1266500661 in words is "one billion, two hundred sixty-six million, five hundred thousand, six hundred sixty-one".