21719259553 has 2 divisors, whose sum is σ = 21719259554. Its totient is φ = 21719259552.

The previous prime is 21719259547. The next prime is 21719259563. The reversal of 21719259553 is 35595291712.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12042209169 + 9677050384 = 109737^2 + 98372^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21719259553 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21719259497 and 21719259506.

It is not a weakly prime, because it can be changed into another prime (21719259503) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10859629776 + 10859629777.

It is an arithmetic number, because the mean of its divisors is an integer number (10859629777).

Almost surely, 2^21719259553 is an apocalyptic number.

It is an amenable number.

21719259553 is a deficient number, since it is larger than the sum of its proper divisors (1).

21719259553 is an equidigital number, since it uses as much as digits as its factorization.

21719259553 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 850500, while the sum is 49.

The spelling of 21719259553 in words is "twenty-one billion, seven hundred nineteen million, two hundred fifty-nine thousand, five hundred fifty-three".