642821570 has 32 divisors (see below), whose sum is σ = 1173864960. Its totient is φ = 253422400.

The previous prime is 642821567. The next prime is 642821573. The reversal of 642821570 is 75128246.

It is an interprime number because it is at equal distance from previous prime (642821567) and next prime (642821573).

It is a self number, because there is not a number n which added to its sum of digits gives 642821570.

It is not an unprimeable number, because it can be changed into a prime (642821573) 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, 240059 + ... + 242721.

It is an arithmetic number, because the mean of its divisors is an integer number (36683280).

Almost surely, 2^642821570 is an apocalyptic number.

642821570 is a deficient number, since it is larger than the sum of its proper divisors (531043390).

642821570 is a wasteful number, since it uses less digits than its factorization.

642821570 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3010.

The product of its (nonzero) digits is 26880, while the sum is 35.

The square root of 642821570 is about 25353.9261259474. The cubic root of 642821570 is about 863.0384545058.

The spelling of 642821570 in words is "six hundred forty-two million, eight hundred twenty-one thousand, five hundred seventy".