905123947 has 12 divisors (see below), whose sum is σ = 1120121040. Its totient is φ = 716141088.

The previous prime is 905123929. The next prime is 905123963. The reversal of 905123947 is 749321509.

It is not a de Polignac number, because 905123947 - 2⁷ = 905123819 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (905123927) 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 in 11 ways as a sum of consecutive naturals, for example, 381372 + ... + 383737.

It is an arithmetic number, because the mean of its divisors is an integer number (93343420).

Almost surely, 2^905123947 is an apocalyptic number.

905123947 is a deficient number, since it is larger than the sum of its proper divisors (214997093).

905123947 is a wasteful number, since it uses less digits than its factorization.

905123947 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 765142 (or 765129 counting only the distinct ones).

The product of its (nonzero) digits is 68040, while the sum is 40.

The square root of 905123947 is about 30085.2779112974. The cubic root of 905123947 is about 967.3181837123.

The spelling of 905123947 in words is "nine hundred five million, one hundred twenty-three thousand, nine hundred forty-seven".