642467481820 has 12 divisors (see below), whose sum is σ = 1349181711864. Its totient is φ = 256986992720.

The previous prime is 642467481781. The next prime is 642467481949. The reversal of 642467481820 is 28184764246.

It is a super-2 number, since 2×642467481820² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16061687026 + ... + 16061687065.

It is an arithmetic number, because the mean of its divisors is an integer number (112431809322).

Almost surely, 2^642467481820 is an apocalyptic number.

It is an amenable number.

642467481820 is an abundant number, since it is smaller than the sum of its proper divisors (706714230044).

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

642467481820 is a wasteful number, since it uses less digits than its factorization.

642467481820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32123374100 (or 32123374098 counting only the distinct ones).

The product of its (nonzero) digits is 4128768, while the sum is 52.

The spelling of 642467481820 in words is "six hundred forty-two billion, four hundred sixty-seven million, four hundred eighty-one thousand, eight hundred twenty".