642500400 has 120 divisors (see below), whose sum is σ = 2147719680. Its totient is φ = 163877120.

The previous prime is 642500399. The next prime is 642500401. The reversal of 642500400 is 4005246.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (642500399) and next prime (642500401).

It is a tau number, because it is divible by the number of its divisors (120).

It is not an unprimeable number, because it can be changed into a prime (642500401) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 15961 + ... + 39239.

It is an arithmetic number, because the mean of its divisors is an integer number (17897664).

Almost surely, 2^642500400 is an apocalyptic number.

642500400 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 642500400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1073859840).

642500400 is an abundant number, since it is smaller than the sum of its proper divisors (1505219280).

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

642500400 is a wasteful number, since it uses less digits than its factorization.

642500400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23323 (or 23312 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 21.

The square root of 642500400 is about 25347.5916015704. The cubic root of 642500400 is about 862.8946985769.

Adding to 642500400 its reverse (4005246), we get a palindrome (646505646).

The spelling of 642500400 in words is "six hundred forty-two million, five hundred thousand, four hundred".