21067760561 has 8 divisors (see below), whose sum is σ = 22332205440. Its totient is φ = 19806111808.

The previous prime is 21067760537. The next prime is 21067760591. The reversal of 21067760561 is 16506776012.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21067760561 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21067760591) 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, 683501 + ... + 713658.

It is an arithmetic number, because the mean of its divisors is an integer number (2791525680).

Almost surely, 2^21067760561 is an apocalyptic number.

It is an amenable number.

21067760561 is a deficient number, since it is larger than the sum of its proper divisors (1264444879).

21067760561 is a wasteful number, since it uses less digits than its factorization.

21067760561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1398063.

The product of its (nonzero) digits is 105840, while the sum is 41.

The spelling of 21067760561 in words is "twenty-one billion, sixty-seven million, seven hundred sixty thousand, five hundred sixty-one".