642821824 has 14 divisors (see below), whose sum is σ = 1275599684. Its totient is φ = 321410880.

The previous prime is 642821791. The next prime is 642821827. The reversal of 642821824 is 428128246.

It is not an unprimeable number, because it can be changed into a prime (642821827) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5021982 + ... + 5022109.

Almost surely, 2^642821824 is an apocalyptic number.

642821824 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

642821824 is a deficient number, since it is larger than the sum of its proper divisors (632777860).

642821824 is a wasteful number, since it uses less digits than its factorization.

642821824 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10044103 (or 10044093 counting only the distinct ones).

The product of its digits is 49152, while the sum is 37.

The square root of 642821824 is about 25353.9311350331. The cubic root of 642821824 is about 863.0385681774.

The spelling of 642821824 in words is "six hundred forty-two million, eight hundred twenty-one thousand, eight hundred twenty-four".