9961645375 has 64 divisors (see below), whose sum is σ = 14426979840. Its totient is φ = 6791040000.

The previous prime is 9961645349. The next prime is 9961645381. The reversal of 9961645375 is 5735461699.

9961645375 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 9961645375 - 2²³ = 9953256767 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (55).

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 63 ways as a sum of consecutive naturals, for example, 2532160 + ... + 2536090.

It is an arithmetic number, because the mean of its divisors is an integer number (225421560).

Almost surely, 2^9961645375 is an apocalyptic number.

9961645375 is a gapful number since it is divisible by the number (95) formed by its first and last digit.

9961645375 is the 53350-th nonagonal number.

9961645375 is a deficient number, since it is larger than the sum of its proper divisors (4465334465).

9961645375 is a wasteful number, since it uses less digits than its factorization.

9961645375 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4073 (or 4063 counting only the distinct ones).

The product of its digits is 6123600, while the sum is 55.

The square root of 9961645375 is about 99808.0426368537. The cubic root of 9961645375 is about 2151.6767431995.

It can be divided in two parts, 99616 and 45375, that added together give a triangular number (144991 = T₅₃₈).

The spelling of 9961645375 in words is "nine billion, nine hundred sixty-one million, six hundred forty-five thousand, three hundred seventy-five".