642280400 has 120 divisors (see below), whose sum is σ = 1690706520. Its totient is φ = 233390080.

The previous prime is 642280381. The next prime is 642280423. The reversal of 642280400 is 4082246.

It can be written as a sum of positive squares in 12 ways, for example, as 19678096 + 622602304 = 4436^2 + 24952^2 .

It is a super-2 number, since 2×642280400² = 825048224448320000, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 642280400.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 195572 + ... + 198828.

It is an arithmetic number, because the mean of its divisors is an integer number (14089221).

Almost surely, 2^642280400 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 642280400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (845353260).

642280400 is an abundant number, since it is smaller than the sum of its proper divisors (1048426120).

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

642280400 is a wasteful number, since it uses less digits than its factorization.

642280400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3321 (or 3310 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 26.

The square root of 642280400 is about 25343.2515672319. The cubic root of 642280400 is about 862.7961987652.

The spelling of 642280400 in words is "six hundred forty-two million, two hundred eighty thousand, four hundred".