1989117601 has 2 divisors, whose sum is σ = 1989117602. Its totient is φ = 1989117600.

The previous prime is 1989117577. The next prime is 1989117629. The reversal of 1989117601 is 1067119891.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1097199376 + 891918225 = 33124^2 + 29865^2 .

It is a cyclic number.

It is not a de Polignac number, because 1989117601 - 2⁹ = 1989117089 is a prime.

It is not a weakly prime, because it can be changed into another prime (1989117001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 994558800 + 994558801.

It is an arithmetic number, because the mean of its divisors is an integer number (994558801).

Almost surely, 2^1989117601 is an apocalyptic number.

It is an amenable number.

1989117601 is a deficient number, since it is larger than the sum of its proper divisors (1).

1989117601 is an equidigital number, since it uses as much as digits as its factorization.

1989117601 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 27216, while the sum is 43.

The square root of 1989117601 is about 44599.5246723550. The cubic root of 1989117601 is about 1257.6317320532.

The spelling of 1989117601 in words is "one billion, nine hundred eighty-nine million, one hundred seventeen thousand, six hundred one".