87778997 has 2 divisors, whose sum is σ = 87778998. Its totient is φ = 87778996.

The previous prime is 87778987. The next prime is 87779023. The reversal of 87778997 is 79987778.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 81558961 + 6220036 = 9031^2 + 2494^2 .

It is a cyclic number.

It is not a de Polignac number, because 87778997 - 2⁴ = 87778981 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (87778907) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43889498 + 43889499.

It is an arithmetic number, because the mean of its divisors is an integer number (43889499).

Almost surely, 2^87778997 is an apocalyptic number.

It is an amenable number.

87778997 is a deficient number, since it is larger than the sum of its proper divisors (1).

87778997 is an equidigital number, since it uses as much as digits as its factorization.

87778997 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12446784, while the sum is 62.

The square root of 87778997 is about 9369.0446151142. The cubic root of 87778997 is about 444.4233527329.

The spelling of 87778997 in words is "eighty-seven million, seven hundred seventy-eight thousand, nine hundred ninety-seven".