642957980 has 48 divisors (see below), whose sum is σ = 1592887296. Its totient is φ = 213330240.

The previous prime is 642957977. The next prime is 642957989. The reversal of 642957980 is 89759246.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642957989) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 69734 + ... + 78413.

It is an arithmetic number, because the mean of its divisors is an integer number (33185152).

Almost surely, 2^642957980 is an apocalyptic number.

It is an amenable number.

642957980 is an abundant number, since it is smaller than the sum of its proper divisors (949929316).

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

642957980 is a wasteful number, since it uses less digits than its factorization.

642957980 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 148194 (or 148192 counting only the distinct ones).

The product of its (nonzero) digits is 1088640, while the sum is 50.

The square root of 642957980 is about 25356.6160991564. The cubic root of 642957980 is about 863.0994972350.

The spelling of 642957980 in words is "six hundred forty-two million, nine hundred fifty-seven thousand, nine hundred eighty".