6991954137 has 24 divisors (see below), whose sum is σ = 11546406144. Its totient is φ = 3993971904.

The previous prime is 6991954133. The next prime is 6991954181. The reversal of 6991954137 is 7314591996.

6991954137 is a `hidden beast` number, since 6 + 9 + 91 + 9 + 541 + 3 + 7 = 666.

It is not a de Polignac number, because 6991954137 - 2² = 6991954133 is a prime.

It is a super-2 number, since 2×6991954137² = 97774845307822829538, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (6991954133) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 172093 + ... + 208805.

It is an arithmetic number, because the mean of its divisors is an integer number (481100256).

Almost surely, 2^6991954137 is an apocalyptic number.

It is an amenable number.

6991954137 is a deficient number, since it is larger than the sum of its proper divisors (4554452007).

6991954137 is a wasteful number, since it uses less digits than its factorization.

6991954137 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39749 (or 39746 counting only the distinct ones).

The product of its digits is 1837080, while the sum is 54.

The square root of 6991954137 is about 83617.9056004155. The cubic root of 6991954137 is about 1912.1979883479.

The spelling of 6991954137 in words is "six billion, nine hundred ninety-one million, nine hundred fifty-four thousand, one hundred thirty-seven".