21790189320145 has 4 divisors (see below), whose sum is σ = 26148227184180. Its totient is φ = 17432151456112.

The previous prime is 21790189320091. The next prime is 21790189320169. The reversal of 21790189320145 is 54102398109712.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 9495790162576 + 12294399157569 = 3081524^2 + 3506337^2 .

It is a cyclic number.

It is not a de Polignac number, because 21790189320145 - 2¹³ = 21790189311953 is a prime.

It is a super-2 number, since 2×21790189320145² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21790189320092 and 21790189320101.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2179018932010 + ... + 2179018932019.

It is an arithmetic number, because the mean of its divisors is an integer number (6537056796045).

Almost surely, 2^{21790189320145} is an apocalyptic number.

It is an amenable number.

21790189320145 is a deficient number, since it is larger than the sum of its proper divisors (4358037864035).

21790189320145 is an equidigital number, since it uses as much as digits as its factorization.

21790189320145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4358037864034.

The product of its (nonzero) digits is 1088640, while the sum is 52.

The spelling of 21790189320145 in words is "twenty-one trillion, seven hundred ninety billion, one hundred eighty-nine million, three hundred twenty thousand, one hundred forty-five".