9961993251 has 96 divisors (see below), whose sum is σ = 18641645568. Its totient is φ = 5184414720.

The previous prime is 9961993247. The next prime is 9961993271. The reversal of 9961993251 is 1523991699.

9961993251 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 9961993251 - 2² = 9961993247 is a prime.

It is not an unprimeable number, because it can be changed into a prime (9961993271) by changing a digit.

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 95 ways as a sum of consecutive naturals, for example, 890871 + ... + 901983.

It is an arithmetic number, because the mean of its divisors is an integer number (194183808).

Almost surely, 2^9961993251 is an apocalyptic number.

9961993251 is a deficient number, since it is larger than the sum of its proper divisors (8679652317).

9961993251 is a wasteful number, since it uses less digits than its factorization.

9961993251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11183 (or 11171 counting only the distinct ones).

The product of its digits is 1180980, while the sum is 54.

The square root of 9961993251 is about 99809.7853469288. The cubic root of 9961993251 is about 2151.7017895299.

The spelling of 9961993251 in words is "nine billion, nine hundred sixty-one million, nine hundred ninety-three thousand, two hundred fifty-one".