275221981 has 2 divisors, whose sum is σ = 275221982. Its totient is φ = 275221980.

The previous prime is 275221967. The next prime is 275222029. The reversal of 275221981 is 189122572.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 256160025 + 19061956 = 16005^2 + 4366^2 .

It is a cyclic number.

It is not a de Polignac number, because 275221981 - 2⁵ = 275221949 is a prime.

It is a super-2 number, since 2×275221981² = 151494277651128722, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 275221981.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (275221901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 137610990 + 137610991.

It is an arithmetic number, because the mean of its divisors is an integer number (137610991).

Almost surely, 2^275221981 is an apocalyptic number.

It is an amenable number.

275221981 is a deficient number, since it is larger than the sum of its proper divisors (1).

275221981 is an equidigital number, since it uses as much as digits as its factorization.

275221981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 20160, while the sum is 37.

The square root of 275221981 is about 16589.8155806507. The cubic root of 275221981 is about 650.4706500579.

The spelling of 275221981 in words is "two hundred seventy-five million, two hundred twenty-one thousand, nine hundred eighty-one".