1264820591 has 2 divisors, whose sum is σ = 1264820592. Its totient is φ = 1264820590.

The previous prime is 1264820549. The next prime is 1264820593. The reversal of 1264820591 is 1950284621.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1264820591 is a prime.

It is a super-2 number, since 2×1264820591² = 3199542254835178562, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 1264820593, 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 (1264820593) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 632410295 + 632410296.

It is an arithmetic number, because the mean of its divisors is an integer number (632410296).

Almost surely, 2^1264820591 is an apocalyptic number.

1264820591 is a deficient number, since it is larger than the sum of its proper divisors (1).

1264820591 is an equidigital number, since it uses as much as digits as its factorization.

1264820591 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 34560, while the sum is 38.

The square root of 1264820591 is about 35564.3162594194. The cubic root of 1264820591 is about 1081.4579620439.

The spelling of 1264820591 in words is "one billion, two hundred sixty-four million, eight hundred twenty thousand, five hundred ninety-one".