654401989 has 2 divisors, whose sum is σ = 654401990. Its totient is φ = 654401988.

The previous prime is 654401977. The next prime is 654401999. The reversal of 654401989 is 989104456.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 565250625 + 89151364 = 23775^2 + 9442^2 .

It is a cyclic number.

It is not a de Polignac number, because 654401989 - 2²¹ = 652304837 is a prime.

It is a super-2 number, since 2×654401989² = 856483926414312242, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (654401939) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 327200994 + 327200995.

It is an arithmetic number, because the mean of its divisors is an integer number (327200995).

Almost surely, 2^654401989 is an apocalyptic number.

It is an amenable number.

654401989 is a deficient number, since it is larger than the sum of its proper divisors (1).

654401989 is an equidigital number, since it uses as much as digits as its factorization.

654401989 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 311040, while the sum is 46.

The square root of 654401989 is about 25581.2820046221. The cubic root of 654401989 is about 868.1901818934.

The spelling of 654401989 in words is "six hundred fifty-four million, four hundred one thousand, nine hundred eighty-nine".