21954494772863 has 2 divisors, whose sum is σ = 21954494772864. Its totient is φ = 21954494772862.

The previous prime is 21954494772851. The next prime is 21954494772871. The reversal of 21954494772863 is 36827749445912.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21954494772863 - 2⁶ = 21954494772799 is a prime.

It is a super-2 number, since 2×21954494772863² (a number of 27 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21954494772823) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10977247386431 + 10977247386432.

It is an arithmetic number, because the mean of its divisors is an integer number (10977247386432).

Almost surely, 2^{21954494772863} is an apocalyptic number.

21954494772863 is a deficient number, since it is larger than the sum of its proper divisors (1).

21954494772863 is an equidigital number, since it uses as much as digits as its factorization.

21954494772863 is an evil number, because the sum of its binary digits is even.

The product of its digits is 731566080, while the sum is 71.

The spelling of 21954494772863 in words is "twenty-one trillion, nine hundred fifty-four billion, four hundred ninety-four million, seven hundred seventy-two thousand, eight hundred sixty-three".