18621926287969 has 9 divisors (see below), whose sum is σ = 18980145878169. Its totient is φ = 18270344791920.

The previous prime is 18621926287957. The next prime is 18621926288011. The reversal of 18621926287969 is 96978262912681.

The square root of 18621926287969 is 4315313.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 11716004808225 + 6905921479744 = 3422865^2 + 2627912^2 .

It is not a de Polignac number, because 18621926287969 - 2²⁷ = 18621792070241 is a prime.

It is a super-2 number, since 2×18621926287969² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18621926287895 and 18621926287904.

It is not an unprimeable number, because it can be changed into a prime (18621926227969) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 228670879 + ... + 228752299.

Almost surely, 2^{18621926287969} is an apocalyptic number.

18621926287969 is the 4315313-rd square number.

18621926287969 is the 2157657-th centered octagonal number.

It is an amenable number.

18621926287969 is a deficient number, since it is larger than the sum of its proper divisors (358219590200).

18621926287969 is an frugal number, since it uses more digits than its factorization.

18621926287969 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 162948 (or 81474 counting only the distinct ones).

The product of its digits is 564350976, while the sum is 76.

The spelling of 18621926287969 in words is "eighteen trillion, six hundred twenty-one billion, nine hundred twenty-six million, two hundred eighty-seven thousand, nine hundred sixty-nine".