291676421 has 2 divisors, whose sum is σ = 291676422. Its totient is φ = 291676420.

The previous prime is 291676397. The next prime is 291676423. The reversal of 291676421 is 124676192.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 170015521 + 121660900 = 13039^2 + 11030^2 .

It is a cyclic number.

It is not a de Polignac number, because 291676421 - 2¹⁴ = 291660037 is a prime.

Together with 291676423, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (291676423) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 145838210 + 145838211.

It is an arithmetic number, because the mean of its divisors is an integer number (145838211).

Almost surely, 2^291676421 is an apocalyptic number.

It is an amenable number.

291676421 is a deficient number, since it is larger than the sum of its proper divisors (1).

291676421 is an equidigital number, since it uses as much as digits as its factorization.

291676421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 36288, while the sum is 38.

The square root of 291676421 is about 17078.5368518500. The cubic root of 291676421 is about 663.1835941956.

The spelling of 291676421 in words is "two hundred ninety-one million, six hundred seventy-six thousand, four hundred twenty-one".