21738167641 has 16 divisors (see below), whose sum is σ = 22246963200. Its totient is φ = 21236202000.

The previous prime is 21738167617. The next prime is 21738167663. The reversal of 21738167641 is 14676183712.

It is a cyclic number.

It is not a de Polignac number, because 21738167641 - 2¹³ = 21738159449 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21738167591 and 21738167600.

It is not an unprimeable number, because it can be changed into a prime (21738167741) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3712366 + ... + 3718216.

It is an arithmetic number, because the mean of its divisors is an integer number (1390435200).

Almost surely, 2^21738167641 is an apocalyptic number.

It is an amenable number.

21738167641 is a deficient number, since it is larger than the sum of its proper divisors (508795559).

21738167641 is a wasteful number, since it uses less digits than its factorization.

21738167641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6420.

The product of its digits is 338688, while the sum is 46.

The spelling of 21738167641 in words is "twenty-one billion, seven hundred thirty-eight million, one hundred sixty-seven thousand, six hundred forty-one".