291921061 has 2 divisors, whose sum is σ = 291921062. Its totient is φ = 291921060.

The previous prime is 291921031. The next prime is 291921103. The reversal of 291921061 is 160129192.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 256992961 + 34928100 = 16031^2 + 5910^2 .

It is a cyclic number.

It is not a de Polignac number, because 291921061 - 2⁵ = 291921029 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (291921011) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 145960530 + 145960531.

It is an arithmetic number, because the mean of its divisors is an integer number (145960531).

Almost surely, 2^291921061 is an apocalyptic number.

It is an amenable number.

291921061 is a deficient number, since it is larger than the sum of its proper divisors (1).

291921061 is an equidigital number, since it uses as much as digits as its factorization.

291921061 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1944, while the sum is 31.

The square root of 291921061 is about 17085.6975567286. The cubic root of 291921061 is about 663.3689547352.

The spelling of 291921061 in words is "two hundred ninety-one million, nine hundred twenty-one thousand, sixty-one".