89889781 has 2 divisors, whose sum is σ = 89889782. Its totient is φ = 89889780.

The previous prime is 89889719. The next prime is 89889799. The reversal of 89889781 is 18798898.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 83887281 + 6002500 = 9159^2 + 2450^2 .

It is a cyclic number.

It is not a de Polignac number, because 89889781 - 2⁹ = 89889269 is a prime.

It is a super-2 number, since 2×89889781² = 16160345456455922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (89889881) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 44944890 + 44944891.

It is an arithmetic number, because the mean of its divisors is an integer number (44944891).

Almost surely, 2^89889781 is an apocalyptic number.

It is an amenable number.

89889781 is a deficient number, since it is larger than the sum of its proper divisors (1).

89889781 is an equidigital number, since it uses as much as digits as its factorization.

89889781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2322432, while the sum is 58.

The square root of 89889781 is about 9481.0221495364. The cubic root of 89889781 is about 447.9574606850.

It can be divided in two parts, 8988 and 9781, that added together give a square (18769 = 137²).

The spelling of 89889781 in words is "eighty-nine million, eight hundred eighty-nine thousand, seven hundred eighty-one".