642691530 has 256 divisors, whose sum is σ = 2032128000. Its totient is φ = 143016192.

The previous prime is 642691529. The next prime is 642691573. The reversal of 642691530 is 35196246.

It is a happy number.

642691530 is a `hidden beast` number, since 64 + 2 + 69 + 1 + 530 = 666.

642691530 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 1533661 + ... + 1534079.

It is an arithmetic number, because the mean of its divisors is an integer number (7938000).

Almost surely, 2^642691530 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 642691530, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1016064000).

642691530 is an abundant number, since it is smaller than the sum of its proper divisors (1389436470).

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

642691530 is a wasteful number, since it uses less digits than its factorization.

642691530 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 490 (or 484 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 36.

The square root of 642691530 is about 25351.3615018997. The cubic root of 642691530 is about 862.9802542760.

The spelling of 642691530 in words is "six hundred forty-two million, six hundred ninety-one thousand, five hundred thirty".