20421655620042 has 8 divisors (see below), whose sum is σ = 40843311240096. Its totient is φ = 6807218540012.

The previous prime is 20421655620013. The next prime is 20421655620077. The reversal of 20421655620042 is 24002655612402.

It is a sphenic number, since it is the product of 3 distinct primes.

20421655620042 is an admirable number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1701804634998 + ... + 1701804635009.

It is an arithmetic number, because the mean of its divisors is an integer number (5105413905012).

Almost surely, 2^{20421655620042} is an apocalyptic number.

20421655620042 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

20421655620042 is a wasteful number, since it uses less digits than its factorization.

20421655620042 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3403609270012.

The product of its (nonzero) digits is 230400, while the sum is 39.

The spelling of 20421655620042 in words is "twenty trillion, four hundred twenty-one billion, six hundred fifty-five million, six hundred twenty thousand, forty-two".