99999978607 has 2 divisors, whose sum is σ = 99999978608. Its totient is φ = 99999978606.

The previous prime is 99999978523. The next prime is 99999978641. The reversal of 99999978607 is 70687999999.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 99999978607 - 2⁷ = 99999978479 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (99999978667) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49999989303 + 49999989304.

It is an arithmetic number, because the mean of its divisors is an integer number (49999989304).

Almost surely, 2^99999978607 is an apocalyptic number.

99999978607 is a deficient number, since it is larger than the sum of its proper divisors (1).

99999978607 is an equidigital number, since it uses as much as digits as its factorization.

99999978607 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1249949232, while the sum is 82.

The spelling of 99999978607 in words is "ninety-nine billion, nine hundred ninety-nine million, nine hundred seventy-eight thousand, six hundred seven".