20421012546 has 160 divisors (see below), whose sum is σ = 53968749120. Its totient is φ = 5703696000.

The previous prime is 20421012539. The next prime is 20421012589. The reversal of 20421012546 is 64521012402.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 1244596 + ... + 1260896.

It is an arithmetic number, because the mean of its divisors is an integer number (337304682).

Almost surely, 2^20421012546 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20421012546, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26984374560).

20421012546 is an abundant number, since it is smaller than the sum of its proper divisors (33547736574).

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

20421012546 is a wasteful number, since it uses less digits than its factorization.

20421012546 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16382 (or 16373 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 27.

Adding to 20421012546 its reverse (64521012402), we get a palindrome (84942024948).

The spelling of 20421012546 in words is "twenty billion, four hundred twenty-one million, twelve thousand, five hundred forty-six".