642389540 has 192 divisors, whose sum is σ = 1646023680. Its totient is φ = 208158720.

The previous prime is 642389509. The next prime is 642389549. The reversal of 642389540 is 45983246.

It is a super-2 number, since 2×642389540² = 825328642202823200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (642389549) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 7217816 + ... + 7217904.

It is an arithmetic number, because the mean of its divisors is an integer number (8573040).

Almost surely, 2^642389540 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 642389540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (823011840).

642389540 is an abundant number, since it is smaller than the sum of its proper divisors (1003634140).

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

642389540 is a wasteful number, since it uses less digits than its factorization.

642389540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 222 (or 220 counting only the distinct ones).

The product of its (nonzero) digits is 207360, while the sum is 41.

The square root of 642389540 is about 25345.4047117027. The cubic root of 642389540 is about 862.8450664373.

The spelling of 642389540 in words is "six hundred forty-two million, three hundred eighty-nine thousand, five hundred forty".