78898509 has 8 divisors (see below), whose sum is σ = 116886720. Its totient is φ = 52598988.

The previous prime is 78898481. The next prime is 78898511. The reversal of 78898509 is 90589887.

It is not a de Polignac number, because 78898509 - 2²¹ = 76801357 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78898409) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1461057 + ... + 1461110.

It is an arithmetic number, because the mean of its divisors is an integer number (14610840).

Almost surely, 2^78898509 is an apocalyptic number.

It is an amenable number.

78898509 is a deficient number, since it is larger than the sum of its proper divisors (37988211).

78898509 is a wasteful number, since it uses less digits than its factorization.

78898509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2922176 (or 2922170 counting only the distinct ones).

The product of its (nonzero) digits is 1451520, while the sum is 54.

The square root of 78898509 is about 8882.4832676454. The cubic root of 78898509 is about 428.9002164131.

The spelling of 78898509 in words is "seventy-eight million, eight hundred ninety-eight thousand, five hundred nine".