6401920 has 64 divisors (see below), whose sum is σ = 17503200. Its totient is φ = 2193408.

The previous prime is 6401893. The next prime is 6401921. The reversal of 6401920 is 291046.

It is a tau number, because it is divible by the number of its divisors (64).

6401920 is a modest number, since divided by 1920 gives 640 as remainder.

It is a junction number, because it is equal to n+sod(n) for n = 6401891 and 6401900.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6401921) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3766 + ... + 5194.

Almost surely, 2^6401920 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6401920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (8751600).

6401920 is an abundant number, since it is smaller than the sum of its proper divisors (11101280).

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

6401920 is a wasteful number, since it uses less digits than its factorization.

6401920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1455 (or 1443 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 22.

The square root of 6401920 is about 2530.2015729977. The cubic root of 6401920 is about 185.6821178435.

Adding to 6401920 its reverse (291046), we get a palindrome (6692966).

The spelling of 6401920 in words is "six million, four hundred one thousand, nine hundred twenty".