9659951491 has 4 divisors (see below), whose sum is σ = 9660238984. Its totient is φ = 9659664000.

The previous prime is 9659951489. The next prime is 9659951549. The reversal of 9659951491 is 1941599569.

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

It is a 7-Lehmer number, since φ(9659951491) divides (9659951491-1)⁷.

It is a cyclic number.

It is not a de Polignac number, because 9659951491 - 2¹ = 9659951489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9659951891) 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, 85470 + ... + 163171.

It is an arithmetic number, because the mean of its divisors is an integer number (2415059746).

Almost surely, 2^9659951491 is an apocalyptic number.

9659951491 is a deficient number, since it is larger than the sum of its proper divisors (287493).

9659951491 is a wasteful number, since it uses less digits than its factorization.

9659951491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 287492.

The product of its digits is 3936600, while the sum is 58.

The square root of 9659951491 is about 98285.0522256564. The cubic root of 9659951491 is about 2129.7321249085.

The spelling of 9659951491 in words is "nine billion, six hundred fifty-nine million, nine hundred fifty-one thousand, four hundred ninety-one".