642398445 has 64 divisors (see below), whose sum is σ = 1245350400. Its totient is φ = 316187712.

The previous prime is 642398443. The next prime is 642398447. The reversal of 642398445 is 544893246.

642398445 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (642398443) and next prime (642398447).

It is not a de Polignac number, because 642398445 - 2¹ = 642398443 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 642398445.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642398443) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 139896 + ... + 144414.

It is an arithmetic number, because the mean of its divisors is an integer number (19458600).

Almost surely, 2^642398445 is an apocalyptic number.

642398445 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

It is an amenable number.

642398445 is a deficient number, since it is larger than the sum of its proper divisors (602951955).

642398445 is an equidigital number, since it uses as much as digits as its factorization.

642398445 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4558 (or 4540 counting only the distinct ones).

The product of its digits is 829440, while the sum is 45.

The square root of 642398445 is about 25345.5803839644. The cubic root of 642398445 is about 862.8490534261.

The spelling of 642398445 in words is "six hundred forty-two million, three hundred ninety-eight thousand, four hundred forty-five".