87780561 has 32 divisors (see below), whose sum is σ = 134369280. Its totient is φ = 50481600.

The previous prime is 87780541. The next prime is 87780577. The reversal of 87780561 is 16508778.

It is not a de Polignac number, because 87780561 - 2¹⁰ = 87779537 is a prime.

It is not an unprimeable number, because it can be changed into a prime (87780521) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 53410 + ... + 55028.

It is an arithmetic number, because the mean of its divisors is an integer number (4199040).

Almost surely, 2^87780561 is an apocalyptic number.

It is an amenable number.

87780561 is a deficient number, since it is larger than the sum of its proper divisors (46588719).

87780561 is a wasteful number, since it uses less digits than its factorization.

87780561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1717.

The product of its (nonzero) digits is 94080, while the sum is 42.

The square root of 87780561 is about 9369.1280810970. The cubic root of 87780561 is about 444.4259922177.

The spelling of 87780561 in words is "eighty-seven million, seven hundred eighty thousand, five hundred sixty-one".