290878321 has 2 divisors, whose sum is σ = 290878322. Its totient is φ = 290878320.

The previous prime is 290878307. The next prime is 290878333. The reversal of 290878321 is 123878092.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 206238321 + 84640000 = 14361^2 + 9200^2 .

It is a cyclic number.

It is not a de Polignac number, because 290878321 - 2⁷ = 290878193 is a prime.

It is a super-2 number, since 2×290878321² = 169220395255558082, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (290878351) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 145439160 + 145439161.

It is an arithmetic number, because the mean of its divisors is an integer number (145439161).

Almost surely, 2^290878321 is an apocalyptic number.

It is an amenable number.

290878321 is a deficient number, since it is larger than the sum of its proper divisors (1).

290878321 is an equidigital number, since it uses as much as digits as its factorization.

290878321 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 48384, while the sum is 40.

The square root of 290878321 is about 17055.1552616797. The cubic root of 290878321 is about 662.5781626540.

The spelling of 290878321 in words is "two hundred ninety million, eight hundred seventy-eight thousand, three hundred twenty-one".