9947868121 has 9 divisors (see below), whose sum is σ = 10569259999. Its totient is φ = 9361103584.

The previous prime is 9947868107. The next prime is 9947868127. The reversal of 9947868121 is 1218687499.

It is a happy number.

The square root of 9947868121 is 99739.

It is a perfect power (a square), and thus also a powerful number.

9947868121 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 7744880025 + 2202988096 = 88005^2 + 46936^2 .

It is not a de Polignac number, because 9947868121 - 2¹⁵ = 9947835353 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9947868127) 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 8 ways as a sum of consecutive naturals, for example, 1692630 + ... + 1698496.

Almost surely, 2^9947868121 is an apocalyptic number.

9947868121 is the 99739-th square number.

9947868121 is the 49870-th centered octagonal number.

It is an amenable number.

9947868121 is a deficient number, since it is larger than the sum of its proper divisors (621391878).

9947868121 is an frugal number, since it uses more digits than its factorization.

9947868121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11768 (or 5884 counting only the distinct ones).

The product of its digits is 1741824, while the sum is 55.

The cubic root of 9947868121 is about 2150.6843410851.

It can be divided in two parts, 99 and 47868121, that added together give a triangular number (47868220 = T₉₇₈₄).

The spelling of 9947868121 in words is "nine billion, nine hundred forty-seven million, eight hundred sixty-eight thousand, one hundred twenty-one".