9186640021 has 8 divisors (see below), whose sum is σ = 9894679704. Its totient is φ = 8478796800.

The previous prime is 9186640007. The next prime is 9186640103. The reversal of 9186640021 is 1200466819.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 827195121 + 8359444900 = 28761^2 + 91430^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 9186640021 - 2⁹ = 9186639509 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9186640121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 56421 + ... + 146821.

It is an arithmetic number, because the mean of its divisors is an integer number (1236834963).

Almost surely, 2^9186640021 is an apocalyptic number.

It is an amenable number.

9186640021 is a deficient number, since it is larger than the sum of its proper divisors (708039683).

9186640021 is a wasteful number, since it uses less digits than its factorization.

9186640021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 98231.

The product of its (nonzero) digits is 20736, while the sum is 37.

The square root of 9186640021 is about 95846.9614594015. The cubic root of 9186640021 is about 2094.3643316112.

The spelling of 9186640021 in words is "nine billion, one hundred eighty-six million, six hundred forty thousand, twenty-one".