989901553 has 2 divisors, whose sum is σ = 989901554. Its totient is φ = 989901552.

The previous prime is 989901547. The next prime is 989901593. The reversal of 989901553 is 355109989.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 508186849 + 481714704 = 22543^2 + 21948^2 .

It is a cyclic number.

It is not a de Polignac number, because 989901553 - 2¹³ = 989893361 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 989901497 and 989901506.

It is not a weakly prime, because it can be changed into another prime (989901593) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 494950776 + 494950777.

It is an arithmetic number, because the mean of its divisors is an integer number (494950777).

Almost surely, 2^989901553 is an apocalyptic number.

It is an amenable number.

989901553 is a deficient number, since it is larger than the sum of its proper divisors (1).

989901553 is an equidigital number, since it uses as much as digits as its factorization.

989901553 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 437400, while the sum is 49.

The square root of 989901553 is about 31462.7009806850. The cubic root of 989901553 is about 996.6224560403.

The spelling of 989901553 in words is "nine hundred eighty-nine million, nine hundred one thousand, five hundred fifty-three".