7978554887 has 2 divisors, whose sum is σ = 7978554888. Its totient is φ = 7978554886.

The previous prime is 7978554877. The next prime is 7978554911. The reversal of 7978554887 is 7884558797.

7978554887 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is an emirp because it is prime and its reverse (7884558797) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 7978554887 - 2¹⁸ = 7978292743 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7978554817) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3989277443 + 3989277444.

It is an arithmetic number, because the mean of its divisors is an integer number (3989277444).

Almost surely, 2^7978554887 is an apocalyptic number.

7978554887 is a deficient number, since it is larger than the sum of its proper divisors (1).

7978554887 is an equidigital number, since it uses as much as digits as its factorization.

7978554887 is an evil number, because the sum of its binary digits is even.

The product of its digits is 158054400, while the sum is 68.

The square root of 7978554887 is about 89322.7568260183. The cubic root of 7978554887 is about 1998.2113080174.

The spelling of 7978554887 in words is "seven billion, nine hundred seventy-eight million, five hundred fifty-four thousand, eight hundred eighty-seven".