20211705161156 has 12 divisors (see below), whose sum is σ = 35370615847980. Its totient is φ = 10105814918880.

The previous prime is 20211705161117. The next prime is 20211705161239. The reversal of 20211705161156 is 65116150711202.

It can be written as a sum of positive squares in 2 ways, for example, as 9551375680900 + 10660329480256 = 3090530^2 + 3265016^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8190215 + ... + 10368366.

It is an arithmetic number, because the mean of its divisors is an integer number (2947551320665).

Almost surely, 2^{20211705161156} is an apocalyptic number.

It is an amenable number.

20211705161156 is a deficient number, since it is larger than the sum of its proper divisors (15158910686824).

20211705161156 is a wasteful number, since it uses less digits than its factorization.

20211705161156 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18830854 (or 18830852 counting only the distinct ones).

The product of its (nonzero) digits is 25200, while the sum is 38.

Adding to 20211705161156 its reverse (65116150711202), we get a palindrome (85327855872358).

The spelling of 20211705161156 in words is "twenty trillion, two hundred eleven billion, seven hundred five million, one hundred sixty-one thousand, one hundred fifty-six".