8720905 has 16 divisors (see below), whose sum is σ = 11289600. Its totient is φ = 6445440.

The previous prime is 8720891. The next prime is 8720911. The reversal of 8720905 is 5090278.

It is not a de Polignac number, because 8720905 - 2¹³ = 8712713 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2776 + ... + 5014.

It is an arithmetic number, because the mean of its divisors is an integer number (705600).

Almost surely, 2^8720905 is an apocalyptic number.

It is an amenable number.

8720905 is a deficient number, since it is larger than the sum of its proper divisors (2568695).

8720905 is a wasteful number, since it uses less digits than its factorization.

8720905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2304.

The product of its (nonzero) digits is 5040, while the sum is 31.

The square root of 8720905 is about 2953.1178439067. The cubic root of 8720905 is about 205.8356136638.

The spelling of 8720905 in words is "eight million, seven hundred twenty thousand, nine hundred five".