21355466401061 has 16 divisors (see below), whose sum is σ = 23029251011760. Its totient is φ = 19686134661120.

The previous prime is 21355466401051. The next prime is 21355466401081. The reversal of 21355466401061 is 16010466455312.

It can be written as a sum of positive squares in 8 ways, for example, as 531850776961 + 20823615624100 = 729281^2 + 4563290^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21355466401061 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21355466401021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 31380341 + ... + 32053653.

It is an arithmetic number, because the mean of its divisors is an integer number (1439328188235).

Almost surely, 2^{21355466401061} is an apocalyptic number.

It is an amenable number.

21355466401061 is a deficient number, since it is larger than the sum of its proper divisors (1673784610699).

21355466401061 is a wasteful number, since it uses less digits than its factorization.

21355466401061 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 676616.

The product of its (nonzero) digits is 518400, while the sum is 44.

The spelling of 21355466401061 in words is "twenty-one trillion, three hundred fifty-five billion, four hundred sixty-six million, four hundred one thousand, sixty-one".