21061343064 has 32 divisors (see below), whose sum is σ = 54942635520. Its totient is φ = 6715210656.

The previous prime is 21061343063. The next prime is 21061343123. The reversal of 21061343064 is 46034316012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21061343063) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 19076752 + ... + 19077855.

It is an arithmetic number, because the mean of its divisors is an integer number (1716957360).

Almost surely, 2^21061343064 is an apocalyptic number.

21061343064 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21061343064 is an abundant number, since it is smaller than the sum of its proper divisors (33881292456).

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

21061343064 is a wasteful number, since it uses less digits than its factorization.

21061343064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38154639 (or 38154635 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 30.

Adding to 21061343064 its reverse (46034316012), we get a palindrome (67095659076).

The spelling of 21061343064 in words is "twenty-one billion, sixty-one million, three hundred forty-three thousand, sixty-four".