21873440651 has 2 divisors, whose sum is σ = 21873440652. Its totient is φ = 21873440650.

The previous prime is 21873440647. The next prime is 21873440671. The reversal of 21873440651 is 15604437812.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21873440651 - 2² = 21873440647 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21873440599 and 21873440608.

It is not a weakly prime, because it can be changed into another prime (21873440671) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10936720325 + 10936720326.

It is an arithmetic number, because the mean of its divisors is an integer number (10936720326).

Almost surely, 2^21873440651 is an apocalyptic number.

21873440651 is a deficient number, since it is larger than the sum of its proper divisors (1).

21873440651 is an equidigital number, since it uses as much as digits as its factorization.

21873440651 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 161280, while the sum is 41.

The spelling of 21873440651 in words is "twenty-one billion, eight hundred seventy-three million, four hundred forty thousand, six hundred fifty-one".