642404400 has 240 divisors, whose sum is σ = 2301602688. Its totient is φ = 151808000.

The previous prime is 642404393. The next prime is 642404401. The reversal of 642404400 is 4404246.

It is a tau number, because it is divible by the number of its divisors (240).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is not an unprimeable number, because it can be changed into a prime (642404401) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 540607 + ... + 541793.

Almost surely, 2^642404400 is an apocalyptic number.

642404400 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 642404400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1150801344).

642404400 is an abundant number, since it is smaller than the sum of its proper divisors (1659198288).

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

642404400 is a wasteful number, since it uses less digits than its factorization.

642404400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1260 (or 1249 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 24.

The square root of 642404400 is about 25345.6978597947. The cubic root of 642404400 is about 862.8517196064.

Adding to 642404400 its reverse (4404246), we get a palindrome (646808646).

The spelling of 642404400 in words is "six hundred forty-two million, four hundred four thousand, four hundred".