8720451 has 6 divisors (see below), whose sum is σ = 12596220. Its totient is φ = 5813628.

The previous prime is 8720447. The next prime is 8720471. The reversal of 8720451 is 1540278.

It is not a de Polignac number, because 8720451 - 2² = 8720447 is a prime.

It is an Ulam number.

8720451 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (8720431) by changing a digit.

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 5 ways as a sum of consecutive naturals, for example, 484461 + ... + 484478.

It is an arithmetic number, because the mean of its divisors is an integer number (2099370).

Almost surely, 2^8720451 is an apocalyptic number.

8720451 is a deficient number, since it is larger than the sum of its proper divisors (3875769).

8720451 is a wasteful number, since it uses less digits than its factorization.

8720451 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 968945 (or 968942 counting only the distinct ones).

The product of its (nonzero) digits is 2240, while the sum is 27.

The square root of 8720451 is about 2953.0409749951. The cubic root of 8720451 is about 205.8320417489.

The spelling of 8720451 in words is "eight million, seven hundred twenty thousand, four hundred fifty-one".