642821147 has 8 divisors (see below), whose sum is σ = 658630896. Its totient is φ = 627050592.

The previous prime is 642821141. The next prime is 642821161. The reversal of 642821147 is 741128246.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 642821147 - 2¹² = 642817051 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (642821141) 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 7 ways as a sum of consecutive naturals, for example, 24893 + ... + 43649.

It is an arithmetic number, because the mean of its divisors is an integer number (82328862).

Almost surely, 2^642821147 is an apocalyptic number.

642821147 is a deficient number, since it is larger than the sum of its proper divisors (15809749).

642821147 is a wasteful number, since it uses less digits than its factorization.

642821147 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19597.

The product of its digits is 21504, while the sum is 35.

The square root of 642821147 is about 25353.9177840428. The cubic root of 642821147 is about 863.0382652022.

The spelling of 642821147 in words is "six hundred forty-two million, eight hundred twenty-one thousand, one hundred forty-seven".