7779989 has 4 divisors (see below), whose sum is σ = 8891424. Its totient is φ = 6668556.

The previous prime is 7779979. The next prime is 7779991. The reversal of 7779989 is 9899777.

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: 9899777 = 127 ⋅77951.

It is a cyclic number.

It is not a de Polignac number, because 7779989 - 2¹² = 7775893 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7779979) 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, 555707 + ... + 555720.

It is an arithmetic number, because the mean of its divisors is an integer number (2222856).

Almost surely, 2^7779989 is an apocalyptic number.

It is an amenable number.

7779989 is a deficient number, since it is larger than the sum of its proper divisors (1111435).

7779989 is a wasteful number, since it uses less digits than its factorization.

7779989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1111434.

The product of its digits is 2000376, while the sum is 56.

The square root of 7779989 is about 2789.2631643500. The cubic root of 7779989 is about 198.1495061687.

The spelling of 7779989 in words is "seven million, seven hundred seventy-nine thousand, nine hundred eighty-nine".