787898989 has 4 divisors (see below), whose sum is σ = 789241824. Its totient is φ = 786556156.

The previous prime is 787898987. The next prime is 787899041. The reversal of 787898989 is 989898787.

787898989 is an esthetic number in base 10, because in such base its adjacent digits differ by 1.

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: 989898787 = 6917 ⋅143111.

It is a cyclic number.

It is not a de Polignac number, because 787898989 - 2¹ = 787898987 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (787898987) 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, 670537 + ... + 671710.

It is an arithmetic number, because the mean of its divisors is an integer number (197310456).

Almost surely, 2^787898989 is an apocalyptic number.

It is an amenable number.

787898989 is a deficient number, since it is larger than the sum of its proper divisors (1342835).

787898989 is a wasteful number, since it uses less digits than its factorization.

787898989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1342834.

The product of its digits is 146313216, while the sum is 73.

The square root of 787898989 is about 28069.5384536333. The cubic root of 787898989 is about 923.6133062829.

It can be divided in two parts, 787898 and 989, that added together give a palindrome (788887).

The spelling of 787898989 in words is "seven hundred eighty-seven million, eight hundred ninety-eight thousand, nine hundred eighty-nine".