6999162921 has 27 divisors (see below), whose sum is σ = 10268584599. Its totient is φ = 4593992832.

The previous prime is 6999162901. The next prime is 6999162923. The reversal of 6999162921 is 1292619996.

The square root of 6999162921 is 83661.

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

6999162921 is a `hidden beast` number, since 6 + 9 + 9 + 9 + 1 + 629 + 2 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 2843555625 + 4155607296 = 53325^2 + 64464^2 .

It is not a de Polignac number, because 6999162921 - 2⁹ = 6999162409 is a prime.

It is not an unprimeable number, because it can be changed into a prime (6999162923) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 19827481 + ... + 19827833.

Almost surely, 2^6999162921 is an apocalyptic number.

6999162921 is the 83661-st square number.

6999162921 is the 41831-st centered octagonal number.

It is an amenable number.

6999162921 is a deficient number, since it is larger than the sum of its proper divisors (3269421678).

6999162921 is an frugal number, since it uses more digits than its factorization.

6999162921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 870 (or 435 counting only the distinct ones).

The product of its digits is 944784, while the sum is 54.

The cubic root of 6999162921 is about 1912.8549285651.

The spelling of 6999162921 in words is "six billion, nine hundred ninety-nine million, one hundred sixty-two thousand, nine hundred twenty-one".