290447981 has 2 divisors, whose sum is σ = 290447982. Its totient is φ = 290447980.

The previous prime is 290447957. The next prime is 290448001. The reversal of 290447981 is 189744092.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 253128100 + 37319881 = 15910^2 + 6109^2 .

It is a cyclic number.

It is not a de Polignac number, because 290447981 - 2⁶ = 290447917 is a prime.

It is a super-2 number, since 2×290447981² = 168720059333952722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (290447951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 145223990 + 145223991.

It is an arithmetic number, because the mean of its divisors is an integer number (145223991).

Almost surely, 2^290447981 is an apocalyptic number.

It is an amenable number.

290447981 is a deficient number, since it is larger than the sum of its proper divisors (1).

290447981 is an equidigital number, since it uses as much as digits as its factorization.

290447981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 145152, while the sum is 44.

The square root of 290447981 is about 17042.5344652725. The cubic root of 290447981 is about 662.2512509119.

The spelling of 290447981 in words is "two hundred ninety million, four hundred forty-seven thousand, nine hundred eighty-one".