11971721654 has 16 divisors (see below), whose sum is σ = 18348650496. Its totient is φ = 5855629800.

The previous prime is 11971721627. The next prime is 11971721677. The reversal of 11971721654 is 45612717911.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 168269 + ... + 228599.

It is an arithmetic number, because the mean of its divisors is an integer number (1146790656).

Almost surely, 2^11971721654 is an apocalyptic number.

11971721654 is a deficient number, since it is larger than the sum of its proper divisors (6376928842).

11971721654 is a wasteful number, since it uses less digits than its factorization.

11971721654 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62491.

The product of its digits is 105840, while the sum is 44.

The spelling of 11971721654 in words is "eleven billion, nine hundred seventy-one million, seven hundred twenty-one thousand, six hundred fifty-four".