9921495645 has 24 divisors (see below), whose sum is σ = 17219916792. Its totient is φ = 5284492800.

The previous prime is 9921495629. The next prime is 9921495653. The reversal of 9921495645 is 5465941299.

9921495645 is a `hidden beast` number, since 9 + 92 + 1 + 495 + 64 + 5 = 666.

9921495645 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 73513476 + 9847982169 = 8574^2 + 99237^2 .

It is not a de Polignac number, because 9921495645 - 2⁴ = 9921495629 is a prime.

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 9921495591 and 9921495600.

It is a congruent number.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 110616 + ... + 179105.

It is an arithmetic number, because the mean of its divisors is an integer number (717496533).

Almost surely, 2^9921495645 is an apocalyptic number.

It is an amenable number.

9921495645 is a deficient number, since it is larger than the sum of its proper divisors (7298421147).

9921495645 is a wasteful number, since it uses less digits than its factorization.

9921495645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 290493 (or 290490 counting only the distinct ones).

The product of its digits is 3499200, while the sum is 54.

The square root of 9921495645 is about 99606.7048195050. The cubic root of 9921495645 is about 2148.7821222280.

The spelling of 9921495645 in words is "nine billion, nine hundred twenty-one million, four hundred ninety-five thousand, six hundred forty-five".