21346404661 has 8 divisors (see below), whose sum is σ = 21386661120. Its totient is φ = 21306178992.

The previous prime is 21346404647. The next prime is 21346404679. The reversal of 21346404661 is 16640464312.

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

It is a cyclic number.

It is not a de Polignac number, because 21346404661 - 2¹⁷ = 21346273589 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21346404661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21346404461) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1736011 + ... + 1748263.

It is an arithmetic number, because the mean of its divisors is an integer number (2673332640).

Almost surely, 2^21346404661 is an apocalyptic number.

It is an amenable number.

21346404661 is a deficient number, since it is larger than the sum of its proper divisors (40256459).

21346404661 is a wasteful number, since it uses less digits than its factorization.

21346404661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15395.

The product of its (nonzero) digits is 82944, while the sum is 37.

Adding to 21346404661 its reverse (16640464312), we get a palindrome (37986868973).

The spelling of 21346404661 in words is "twenty-one billion, three hundred forty-six million, four hundred four thousand, six hundred sixty-one".