20421534136016 has 80 divisors (see below), whose sum is σ = 44126571926976. Its totient is φ = 9095212320768.

The previous prime is 20421534136009. The next prime is 20421534136067. The reversal of 20421534136016 is 61063143512402.

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 15 ways as a sum of consecutive naturals, for example, 13012265 + ... + 14496968.

Almost surely, 2^{20421534136016} is an apocalyptic number.

20421534136016 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

20421534136016 is an abundant number, since it is smaller than the sum of its proper divisors (23705037790960).

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

20421534136016 is a wasteful number, since it uses less digits than its factorization.

20421534136016 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27509380 (or 27509374 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 38.

Adding to 20421534136016 its reverse (61063143512402), we get a palindrome (81484677648418).

The spelling of 20421534136016 in words is "twenty trillion, four hundred twenty-one billion, five hundred thirty-four million, one hundred thirty-six thousand, sixteen".