6991969924 has 9 divisors (see below), whose sum is σ = 12236240037. Its totient is φ = 3495901344.

The previous prime is 6991969889. The next prime is 6991969937. The reversal of 6991969924 is 4299691996.

The square root of 6991969924 is 83618.

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

It can be written as a sum of positive squares in only one way, i.e., 2114344324 + 4877625600 = 45982^2 + 69840^2 .

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 146332 + ... + 188140.

Almost surely, 2^6991969924 is an apocalyptic number.

6991969924 is the 83618-th square number.

It is an amenable number.

6991969924 is a deficient number, since it is larger than the sum of its proper divisors (5244270113).

6991969924 is an frugal number, since it uses more digits than its factorization.

6991969924 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83622 (or 41811 counting only the distinct ones).

The product of its digits is 17006112, while the sum is 64.

The cubic root of 6991969924 is about 1912.1994275186.

Multiplying 6991969924 by its sum of digits (64), we get a square (447486075136 = 668944²).

The spelling of 6991969924 in words is "six billion, nine hundred ninety-one million, nine hundred sixty-nine thousand, nine hundred twenty-four".