18220039261 has 2 divisors, whose sum is σ = 18220039262. Its totient is φ = 18220039260.

The previous prime is 18220039247. The next prime is 18220039333. The reversal of 18220039261 is 16293002281.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17338305625 + 881733636 = 131675^2 + 29694^2 .

It is a cyclic number.

It is not a de Polignac number, because 18220039261 - 2⁷ = 18220039133 is a prime.

It is a super-2 number, since 2×18220039261² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18220039661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9110019630 + 9110019631.

It is an arithmetic number, because the mean of its divisors is an integer number (9110019631).

Almost surely, 2^18220039261 is an apocalyptic number.

It is an amenable number.

18220039261 is a deficient number, since it is larger than the sum of its proper divisors (1).

18220039261 is an equidigital number, since it uses as much as digits as its factorization.

18220039261 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10368, while the sum is 34.

The spelling of 18220039261 in words is "eighteen billion, two hundred twenty million, thirty-nine thousand, two hundred sixty-one".