87780805 has 12 divisors (see below), whose sum is σ = 122535180. Its totient is φ = 60192384.

The previous prime is 87780793. The next prime is 87780827. The reversal of 87780805 is 50808778.

It can be written as a sum of positive squares in 2 ways, for example, as 14130081 + 73650724 = 3759^2 + 8582^2 .

It is not a de Polignac number, because 87780805 - 2¹⁷ = 87649733 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 178900 + ... + 179389.

It is an arithmetic number, because the mean of its divisors is an integer number (10211265).

Almost surely, 2^87780805 is an apocalyptic number.

It is an amenable number.

87780805 is a deficient number, since it is larger than the sum of its proper divisors (34754375).

87780805 is a wasteful number, since it uses less digits than its factorization.

87780805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 358308 (or 358301 counting only the distinct ones).

The product of its (nonzero) digits is 125440, while the sum is 43.

The square root of 87780805 is about 9369.1411025771. The cubic root of 87780805 is about 444.4264040015.

The spelling of 87780805 in words is "eighty-seven million, seven hundred eighty thousand, eight hundred five".