9875511661 has 4 divisors (see below), whose sum is σ = 9901568800. Its totient is φ = 9849454524.

The previous prime is 9875511601. The next prime is 9875511673. The reversal of 9875511661 is 1661155789.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 9875511661 - 2²⁹ = 9338640749 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 (9875511601) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13028001 + ... + 13028758.

It is an arithmetic number, because the mean of its divisors is an integer number (2475392200).

Almost surely, 2^9875511661 is an apocalyptic number.

It is an amenable number.

9875511661 is a deficient number, since it is larger than the sum of its proper divisors (26057139).

9875511661 is a wasteful number, since it uses less digits than its factorization.

9875511661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26057138.

The product of its digits is 453600, while the sum is 49.

The square root of 9875511661 is about 99375.6089842976. The cubic root of 9875511661 is about 2145.4572669779.

The spelling of 9875511661 in words is "nine billion, eight hundred seventy-five million, five hundred eleven thousand, six hundred sixty-one".