78486989 has 4 divisors (see below), whose sum is σ = 89699424. Its totient is φ = 67274556.

The previous prime is 78486983. The next prime is 78487001. The reversal of 78486989 is 98968487.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 98968487 = 7193 ⋅13759.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78486989 is a prime.

It is a super-2 number, since 2×78486989² = 12320414884572242, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78486983) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5606207 + ... + 5606220.

It is an arithmetic number, because the mean of its divisors is an integer number (22424856).

Almost surely, 2^78486989 is an apocalyptic number.

It is an amenable number.

78486989 is a deficient number, since it is larger than the sum of its proper divisors (11212435).

78486989 is a wasteful number, since it uses less digits than its factorization.

78486989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11212434.

The product of its digits is 6967296, while the sum is 59.

The square root of 78486989 is about 8859.2882896991. The cubic root of 78486989 is about 428.1532281741.

The spelling of 78486989 in words is "seventy-eight million, four hundred eighty-six thousand, nine hundred eighty-nine".