864921947 has 2 divisors, whose sum is σ = 864921948. Its totient is φ = 864921946.

The previous prime is 864921931. The next prime is 864921997. The reversal of 864921947 is 749129468.

It is an a-pointer prime, because the next prime (864921997) can be obtained adding 864921947 to its sum of digits (50).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 864921947 - 2⁴ = 864921931 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 864921895 and 864921904.

It is not a weakly prime, because it can be changed into another prime (864921907) 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, 432460973 + 432460974.

It is an arithmetic number, because the mean of its divisors is an integer number (432460974).

Almost surely, 2^864921947 is an apocalyptic number.

864921947 is a deficient number, since it is larger than the sum of its proper divisors (1).

864921947 is an equidigital number, since it uses as much as digits as its factorization.

864921947 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 870912, while the sum is 50.

The square root of 864921947 is about 29409.5553689613. Note that the first 3 decimals coincide. The cubic root of 864921947 is about 952.7792838186.

The spelling of 864921947 in words is "eight hundred sixty-four million, nine hundred twenty-one thousand, nine hundred forty-seven".