21103667641 has 32 divisors (see below), whose sum is σ = 25849087488. Its totient is φ = 16835765760.

The previous prime is 21103667617. The next prime is 21103667647. The reversal of 21103667641 is 14676630112.

It is a cyclic number.

It is not a de Polignac number, because 21103667641 - 2⁵ = 21103667609 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21103667641.

It is not an unprimeable number, because it can be changed into a prime (21103667647) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2616571 + ... + 2624623.

It is an arithmetic number, because the mean of its divisors is an integer number (807783984).

Almost surely, 2^21103667641 is an apocalyptic number.

It is an amenable number.

21103667641 is a deficient number, since it is larger than the sum of its proper divisors (4745419847).

21103667641 is a wasteful number, since it uses less digits than its factorization.

21103667641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8521.

The product of its (nonzero) digits is 36288, while the sum is 37.

The spelling of 21103667641 in words is "twenty-one billion, one hundred three million, six hundred sixty-seven thousand, six hundred forty-one".