21694104082249 has 9 divisors (see below), whose sum is σ = 22111401477109. Its totient is φ = 21284539163680.

The previous prime is 21694104082219. The next prime is 21694104082279. The reversal of 21694104082249 is 94228040149612.

The square root of 21694104082249 is 4657693.

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

It is an interprime number because it is at equal distance from previous prime (21694104082219) and next prime (21694104082279).

It can be written as a sum of positive squares in 4 ways, for example, as 3812471028025 + 17881633054224 = 1952555^2 + 4228668^2 .

It is not a de Polignac number, because 21694104082249 - 2¹³ = 21694104074057 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21694104082196 and 21694104082205.

It is not an unprimeable number, because it can be changed into a prime (21694104082219) 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, 246813789 + ... + 246901669.

Almost surely, 2^{21694104082249} is an apocalyptic number.

21694104082249 is the 4657693-rd square number.

21694104082249 is the 2328847-th centered octagonal number.

It is an amenable number.

21694104082249 is a deficient number, since it is larger than the sum of its proper divisors (417297394860).

21694104082249 is an frugal number, since it uses more digits than its factorization.

21694104082249 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 175868 (or 87934 counting only the distinct ones).

The product of its (nonzero) digits is 1990656, while the sum is 52.

The spelling of 21694104082249 in words is "twenty-one trillion, six hundred ninety-four billion, one hundred four million, eighty-two thousand, two hundred forty-nine".