6401920144 has 45 divisors (see below), whose sum is σ = 12607274649. Its totient is φ = 3149272320.

The previous prime is 6401920123. The next prime is 6401920157. The reversal of 6401920144 is 4410291046.

The square root of 6401920144 is 80012.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 4814694544 + 1587225600 = 69388^2 + 39840^2 .

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 26563864 + ... + 26564104.

Almost surely, 2^6401920144 is an apocalyptic number.

6401920144 is the 80012-nd square number.

It is an amenable number.

6401920144 is a deficient number, since it is larger than the sum of its proper divisors (6205354505).

6401920144 is an frugal number, since it uses more digits than its factorization.

6401920144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 656 (or 326 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 31.

The cubic root of 6401920144 is about 1856.8211923572.

The spelling of 6401920144 in words is "six billion, four hundred one million, nine hundred twenty thousand, one hundred forty-four".