11661651 has 10 divisors (see below), whose sum is σ = 17420612. Its totient is φ = 7774380.

The previous prime is 11661619. The next prime is 11661653. The reversal of 11661651 is 15616611.

11661651 is a `hidden beast` number, since 1 + 1 + 6 + 6 + 1 + 651 = 666.

It is not a de Polignac number, because 11661651 - 2⁵ = 11661619 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11661653) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 71905 + ... + 72066.

Almost surely, 2^11661651 is an apocalyptic number.

11661651 is a deficient number, since it is larger than the sum of its proper divisors (5758961).

11661651 is an equidigital number, since it uses as much as digits as its factorization.

11661651 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 143983 (or 143974 counting only the distinct ones).

The product of its digits is 1080, while the sum is 27.

The square root of 11661651 is about 3414.9159579703. The cubic root of 11661651 is about 226.7705639130.

The spelling of 11661651 in words is "eleven million, six hundred sixty-one thousand, six hundred fifty-one".