489787981 has 8 divisors (see below), whose sum is σ = 503327480. Its totient is φ = 476264448.

The previous prime is 489787973. The next prime is 489787993. The reversal of 489787981 is 189787984.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 72403081 + 417384900 = 8509^2 + 20430^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 489787981 - 2³ = 489787973 is a prime.

It is a super-2 number, since 2×489787981² = 479784532664112722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (489787951) 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, 85165 + ... + 90733.

It is an arithmetic number, because the mean of its divisors is an integer number (62915935).

Almost surely, 2^489787981 is an apocalyptic number.

It is an amenable number.

489787981 is a deficient number, since it is larger than the sum of its proper divisors (13539499).

489787981 is a wasteful number, since it uses less digits than its factorization.

489787981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7983.

The product of its digits is 8128512, while the sum is 61.

The square root of 489787981 is about 22131.1540819723. The cubic root of 489787981 is about 788.2597923115.

The spelling of 489787981 in words is "four hundred eighty-nine million, seven hundred eighty-seven thousand, nine hundred eighty-one".