489979921 has 2 divisors, whose sum is σ = 489979922. Its totient is φ = 489979920.

The previous prime is 489979907. The next prime is 489979927. The reversal of 489979921 is 129979984.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 421686225 + 68293696 = 20535^2 + 8264^2 .

It is a cyclic number.

It is not a de Polignac number, because 489979921 - 2¹⁹ = 489455633 is a prime.

It is not a weakly prime, because it can be changed into another prime (489979927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 244989960 + 244989961.

It is an arithmetic number, because the mean of its divisors is an integer number (244989961).

Almost surely, 2^489979921 is an apocalyptic number.

It is an amenable number.

489979921 is a deficient number, since it is larger than the sum of its proper divisors (1).

489979921 is an equidigital number, since it uses as much as digits as its factorization.

489979921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2939328, while the sum is 58.

The square root of 489979921 is about 22135.4900781528. The cubic root of 489979921 is about 788.3627476248.

The spelling of 489979921 in words is "four hundred eighty-nine million, nine hundred seventy-nine thousand, nine hundred twenty-one".