289999999921 has 2 divisors, whose sum is σ = 289999999922. Its totient is φ = 289999999920.

The previous prime is 289999999903. The next prime is 289999999987. The reversal of 289999999921 is 129999999982.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 163025367696 + 126974632225 = 403764^2 + 356335^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-289999999921 is a prime.

It is not a weakly prime, because it can be changed into another prime (289999979921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 144999999960 + 144999999961.

It is an arithmetic number, because the mean of its divisors is an integer number (144999999961).

Almost surely, 2^289999999921 is an apocalyptic number.

It is an amenable number.

289999999921 is a deficient number, since it is larger than the sum of its proper divisors (1).

289999999921 is an equidigital number, since it uses as much as digits as its factorization.

289999999921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1377495072, while the sum is 85.

The spelling of 289999999921 in words is "two hundred eighty-nine billion, nine hundred ninety-nine million, nine hundred ninety-nine thousand, nine hundred twenty-one".