275951981 has 4 divisors (see below), whose sum is σ = 276430812. Its totient is φ = 275473152.

The previous prime is 275951971. The next prime is 275952011. The reversal of 275951981 is 189159572.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 171217225 + 104734756 = 13085^2 + 10234^2 .

It is a cyclic number.

It is not a de Polignac number, because 275951981 - 2⁶ = 275951917 is a prime.

It is a super-2 number, since 2×275951981² = 152298991635648722, which 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 (275951971) 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, 238550 + ... + 239703.

It is an arithmetic number, because the mean of its divisors is an integer number (69107703).

Almost surely, 2^275951981 is an apocalyptic number.

It is an amenable number.

275951981 is a deficient number, since it is larger than the sum of its proper divisors (478831).

275951981 is an equidigital number, since it uses as much as digits as its factorization.

275951981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 478830.

The product of its digits is 226800, while the sum is 47.

The square root of 275951981 is about 16611.8024609011. The cubic root of 275951981 is about 651.0452460799.

The spelling of 275951981 in words is "two hundred seventy-five million, nine hundred fifty-one thousand, nine hundred eighty-one".