87780842 has 4 divisors (see below), whose sum is σ = 131671266. Its totient is φ = 43890420.

The previous prime is 87780827. The next prime is 87780859. The reversal of 87780842 is 24808778.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 24808778 = 2 ⋅12404389.

It can be written as a sum of positive squares in only one way, i.e., 73119601 + 14661241 = 8551^2 + 3829^2 .

It is a junction number, because it is equal to n+sod(n) for n = 87780793 and 87780802.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 21945209 + ... + 21945212.

Almost surely, 2^87780842 is an apocalyptic number.

87780842 is a deficient number, since it is larger than the sum of its proper divisors (43890424).

87780842 is a wasteful number, since it uses less digits than its factorization.

87780842 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43890423.

The product of its (nonzero) digits is 200704, while the sum is 44.

The square root of 87780842 is about 9369.1430771442. The cubic root of 87780842 is about 444.4264664441.

The spelling of 87780842 in words is "eighty-seven million, seven hundred eighty thousand, eight hundred forty-two".