87779999 has 4 divisors (see below), whose sum is σ = 88632336. Its totient is φ = 86927664.

The previous prime is 87779977. The next prime is 87780001. The reversal of 87779999 is 99997778.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 87779999 - 2⁸ = 87779743 is a prime.

It is a Duffinian number.

87779999 is a modest number, since divided by 9999 gives 8777 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (87779929) 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 3 ways as a sum of consecutive naturals, for example, 426014 + ... + 426219.

It is an arithmetic number, because the mean of its divisors is an integer number (22158084).

Almost surely, 2^87779999 is an apocalyptic number.

87779999 is a deficient number, since it is larger than the sum of its proper divisors (852337).

87779999 is a wasteful number, since it uses less digits than its factorization.

87779999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 852336.

The product of its digits is 18003384, while the sum is 65.

The square root of 87779999 is about 9369.0980889304. The cubic root of 87779999 is about 444.4250437619.

The spelling of 87779999 in words is "eighty-seven million, seven hundred seventy-nine thousand, nine hundred ninety-nine".