642406020 has 24 divisors (see below), whose sum is σ = 1798737024. Its totient is φ = 171308256.

The previous prime is 642406019. The next prime is 642406021. The reversal of 642406020 is 20604246.

It is an interprime number because it is at equal distance from previous prime (642406019) and next prime (642406021).

It is not an unprimeable number, because it can be changed into a prime (642406021) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5353324 + ... + 5353443.

It is an arithmetic number, because the mean of its divisors is an integer number (74947376).

Almost surely, 2^642406020 is an apocalyptic number.

642406020 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

642406020 is an abundant number, since it is smaller than the sum of its proper divisors (1156331004).

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

642406020 is a wasteful number, since it uses less digits than its factorization.

642406020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10706779 (or 10706777 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 24.

The square root of 642406020 is about 25345.7298178608. The cubic root of 642406020 is about 862.8524449121.

The spelling of 642406020 in words is "six hundred forty-two million, four hundred six thousand, twenty".