642025440 has 432 divisors, whose sum is σ = 2650847472. Its totient is φ = 146313216.

The previous prime is 642025399. The next prime is 642025481. The reversal of 642025440 is 44520246.

It is an interprime number because it is at equal distance from previous prime (642025399) and next prime (642025481).

It is a tau number, because it is divible by the number of its divisors (432).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 1904952 + ... + 1905288.

It is an arithmetic number, because the mean of its divisors is an integer number (6136221).

Almost surely, 2^642025440 is an apocalyptic number.

642025440 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 642025440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1325423736).

642025440 is an abundant number, since it is smaller than the sum of its proper divisors (2008822032).

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

642025440 is a wasteful number, since it uses less digits than its factorization.

642025440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 381 (or 354 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 27.

The square root of 642025440 is about 25338.2209320228. The cubic root of 642025440 is about 862.6820182957.

Adding to 642025440 its reverse (44520246), we get a palindrome (686545686).

The spelling of 642025440 in words is "six hundred forty-two million, twenty-five thousand, four hundred forty".