21844607737 has 2 divisors, whose sum is σ = 21844607738. Its totient is φ = 21844607736.

The previous prime is 21844607723. The next prime is 21844607749. The reversal of 21844607737 is 73770644812.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21293813776 + 550793961 = 145924^2 + 23469^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21844607737 is a prime.

It is a super-2 number, since 2×21844607737² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21844607717) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10922303868 + 10922303869.

It is an arithmetic number, because the mean of its divisors is an integer number (10922303869).

Almost surely, 2^21844607737 is an apocalyptic number.

It is an amenable number.

21844607737 is a deficient number, since it is larger than the sum of its proper divisors (1).

21844607737 is an equidigital number, since it uses as much as digits as its factorization.

21844607737 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1580544, while the sum is 49.

The spelling of 21844607737 in words is "twenty-one billion, eight hundred forty-four million, six hundred seven thousand, seven hundred thirty-seven".