211571201081 has 2 divisors, whose sum is σ = 211571201082. Its totient is φ = 211571201080.

The previous prime is 211571201057. The next prime is 211571201137. The reversal of 211571201081 is 180102175112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 180362445481 + 31208755600 = 424691^2 + 176660^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-211571201081 is a prime.

It is a super-2 number, since 2×211571201081² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (211571209081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105785600540 + 105785600541.

It is an arithmetic number, because the mean of its divisors is an integer number (105785600541).

Almost surely, 2^211571201081 is an apocalyptic number.

It is an amenable number.

211571201081 is a deficient number, since it is larger than the sum of its proper divisors (1).

211571201081 is an equidigital number, since it uses as much as digits as its factorization.

211571201081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1120, while the sum is 29.

Adding to 211571201081 its reverse (180102175112), we get a palindrome (391673376193).

The spelling of 211571201081 in words is "two hundred eleven billion, five hundred seventy-one million, two hundred one thousand, eighty-one".