101666551 has 4 divisors (see below), whose sum is σ = 116190352. Its totient is φ = 87142752.

The previous prime is 101666527. The next prime is 101666557. The reversal of 101666551 is 155666101.

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

It is a cyclic number.

It is not a de Polignac number, because 101666551 - 2⁹ = 101666039 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 (101666557) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7261890 + ... + 7261903.

It is an arithmetic number, because the mean of its divisors is an integer number (29047588).

Almost surely, 2^101666551 is an apocalyptic number.

101666551 is a deficient number, since it is larger than the sum of its proper divisors (14523801).

101666551 is an equidigital number, since it uses as much as digits as its factorization.

101666551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14523800.

The product of its (nonzero) digits is 5400, while the sum is 31.

The square root of 101666551 is about 10082.9832391014. The cubic root of 101666551 is about 466.7231721261.

The spelling of 101666551 in words is "one hundred one million, six hundred sixty-six thousand, five hundred fifty-one".