9961891694 has 4 divisors (see below), whose sum is σ = 14942837544. Its totient is φ = 4980945846.

The previous prime is 9961891679. The next prime is 9961891699. The reversal of 9961891694 is 4961981699.

It is a happy number.

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

It is a super-2 number, since 2×9961891694² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9961891699) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2490472922 + ... + 2490472925.

It is an arithmetic number, because the mean of its divisors is an integer number (3735709386).

Almost surely, 2^9961891694 is an apocalyptic number.

9961891694 is a deficient number, since it is larger than the sum of its proper divisors (4980945850).

9961891694 is a wasteful number, since it uses less digits than its factorization.

9961891694 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4980945849.

The product of its digits is 7558272, while the sum is 62.

The square root of 9961891694 is about 99809.2765929099. The cubic root of 9961891694 is about 2151.6944777027.

The spelling of 9961891694 in words is "nine billion, nine hundred sixty-one million, eight hundred ninety-one thousand, six hundred ninety-four".