1897773494409 has 27 divisors (see below), whose sum is σ = 2968396424487. Its totient is φ = 1167827549616.

The previous prime is 1897773494369. The next prime is 1897773494413. The reversal of 1897773494409 is 9044943777981.

The square root of 1897773494409 is 1377597.

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

1897773494409 is a `hidden beast` number, since 1 + 8 + 9 + 77 + 73 + 49 + 440 + 9 = 666.

It can be written as a sum of positive squares in only one way, i.e., 280735724025 + 1617037770384 = 529845^2 + 1271628^2 .

It is not a de Polignac number, because 1897773494409 - 2²¹ = 1897771397257 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1897773494429) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 53708622 + ... + 53743944.

Almost surely, 2^{1897773494409} is an apocalyptic number.

1897773494409 is the 1377597-th square number.

1897773494409 is the 688799-th centered octagonal number.

It is an amenable number.

1897773494409 is a deficient number, since it is larger than the sum of its proper divisors (1070622930078).

1897773494409 is an frugal number, since it uses more digits than its factorization.

1897773494409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70678 (or 35339 counting only the distinct ones).

The product of its (nonzero) digits is 384072192, while the sum is 72.

The spelling of 1897773494409 in words is "one trillion, eight hundred ninety-seven billion, seven hundred seventy-three million, four hundred ninety-four thousand, four hundred nine".