21819670349409 has 45 divisors (see below), whose sum is σ = 32920876317153. Its totient is φ = 14402360514168.

The previous prime is 21819670349383. The next prime is 21819670349417. The reversal of 21819670349409 is 90494307691812.

The square root of 21819670349409 is 4671153.

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

21819670349409 is a `hidden beast` number, since 2 + 1 + 8 + 196 + 7 + 0 + 34 + 9 + 409 = 666.

It is not a de Polignac number, because 21819670349409 - 2¹⁵ = 21819670316641 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21819670349459) by changing a digit.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 4330156312 + ... + 4330161350.

Almost surely, 2^{21819670349409} is an apocalyptic number.

21819670349409 is the 4671153-rd square number.

21819670349409 is the 2335577-th centered octagonal number.

It is an amenable number.

21819670349409 is a deficient number, since it is larger than the sum of its proper divisors (11101205967744).

21819670349409 is an frugal number, since it uses more digits than its factorization.

21819670349409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10296 (or 5145 counting only the distinct ones).

The product of its (nonzero) digits is 23514624, while the sum is 63.

The spelling of 21819670349409 in words is "twenty-one trillion, eight hundred nineteen billion, six hundred seventy million, three hundred forty-nine thousand, four hundred nine".