642660420 has 24 divisors (see below), whose sum is σ = 1799449344. Its totient is φ = 171376096.

The previous prime is 642660419. The next prime is 642660433. The reversal of 642660420 is 24066246.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5355444 + ... + 5355563.

It is an arithmetic number, because the mean of its divisors is an integer number (74977056).

Almost surely, 2^642660420 is an apocalyptic number.

642660420 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

642660420 is an abundant number, since it is smaller than the sum of its proper divisors (1156788924).

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

642660420 is a wasteful number, since it uses less digits than its factorization.

642660420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10711019 (or 10711017 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 30.

The square root of 642660420 is about 25350.7479179609. The cubic root of 642660420 is about 862.9663296337.

The spelling of 642660420 in words is "six hundred forty-two million, six hundred sixty thousand, four hundred twenty".