21844607749 has 2 divisors, whose sum is σ = 21844607750. Its totient is φ = 21844607748.

The previous prime is 21844607737. The next prime is 21844607767. The reversal of 21844607749 is 94770644812.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16235346724 + 5609261025 = 127418^2 + 74895^2 .

It is a cyclic number.

It is not a de Polignac number, because 21844607749 - 2⁵ = 21844607717 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21844607696 and 21844607705.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21844607779) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10922303874 + 10922303875.

It is an arithmetic number, because the mean of its divisors is an integer number (10922303875).

Almost surely, 2^21844607749 is an apocalyptic number.

It is an amenable number.

21844607749 is a deficient number, since it is larger than the sum of its proper divisors (1).

21844607749 is an equidigital number, since it uses as much as digits as its factorization.

21844607749 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2709504, while the sum is 52.

The spelling of 21844607749 in words is "twenty-one billion, eight hundred forty-four million, six hundred seven thousand, seven hundred forty-nine".