11821656071 has 4 divisors (see below), whose sum is σ = 11943528912. Its totient is φ = 11699783232.

The previous prime is 11821656023. The next prime is 11821656079. The reversal of 11821656071 is 17065612811.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11821656071 is a prime.

It is a super-2 number, since 2×11821656071² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11821656079) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 60936275 + ... + 60936468.

It is an arithmetic number, because the mean of its divisors is an integer number (2985882228).

Almost surely, 2^11821656071 is an apocalyptic number.

11821656071 is a deficient number, since it is larger than the sum of its proper divisors (121872841).

11821656071 is an equidigital number, since it uses as much as digits as its factorization.

11821656071 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 121872840.

The product of its (nonzero) digits is 20160, while the sum is 38.

The spelling of 11821656071 in words is "eleven billion, eight hundred twenty-one million, six hundred fifty-six thousand, seventy-one".