1644553398 has 16 divisors (see below), whose sum is σ = 3462217920. Its totient is φ = 519332616.

The previous prime is 1644553381. The next prime is 1644553457. The reversal of 1644553398 is 8933554461.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7212840 + ... + 7213067.

It is an arithmetic number, because the mean of its divisors is an integer number (216388620).

Almost surely, 2^1644553398 is an apocalyptic number.

1644553398 is an abundant number, since it is smaller than the sum of its proper divisors (1817664522).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1644553398 is a wasteful number, since it uses less digits than its factorization.

1644553398 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14425931.

The product of its digits is 1555200, while the sum is 48.

The square root of 1644553398 is about 40553.0935688019. The cubic root of 1644553398 is about 1180.3641024255.

The spelling of 1644553398 in words is "one billion, six hundred forty-four million, five hundred fifty-three thousand, three hundred ninety-eight".