291081601 has 2 divisors, whose sum is σ = 291081602. Its totient is φ = 291081600.

The previous prime is 291081589. The next prime is 291081641. The reversal of 291081601 is 106180192.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 276058225 + 15023376 = 16615^2 + 3876^2 .

It is a cyclic number.

It is not a de Polignac number, because 291081601 - 2¹⁵ = 291048833 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 291081601.

It is not a weakly prime, because it can be changed into another prime (291081641) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 145540800 + 145540801.

It is an arithmetic number, because the mean of its divisors is an integer number (145540801).

Almost surely, 2^291081601 is an apocalyptic number.

It is an amenable number.

291081601 is a deficient number, since it is larger than the sum of its proper divisors (1).

291081601 is an equidigital number, since it uses as much as digits as its factorization.

291081601 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 864, while the sum is 28.

The square root of 291081601 is about 17061.1137092512. The cubic root of 291081601 is about 662.7324740569.

The spelling of 291081601 in words is "two hundred ninety-one million, eighty-one thousand, six hundred one".