21018651103 has 2 divisors, whose sum is σ = 21018651104. Its totient is φ = 21018651102.

The previous prime is 21018651053. The next prime is 21018651127. The reversal of 21018651103 is 30115681012.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21018651103 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21018654103) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10509325551 + 10509325552.

It is an arithmetic number, because the mean of its divisors is an integer number (10509325552).

Almost surely, 2^21018651103 is an apocalyptic number.

21018651103 is a deficient number, since it is larger than the sum of its proper divisors (1).

21018651103 is an equidigital number, since it uses as much as digits as its factorization.

21018651103 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1440, while the sum is 28.

The spelling of 21018651103 in words is "twenty-one billion, eighteen million, six hundred fifty-one thousand, one hundred three".