1912105418521 has 9 divisors (see below), whose sum is σ = 1923462582429. Its totient is φ = 1900814946336.

The previous prime is 1912105418519. The next prime is 1912105418549. The reversal of 1912105418521 is 1258145012191.

The square root of 1912105418521 is 1382789.

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 24890121 + 1912080528400 = 4989^2 + 1382780^2 .

It is not a de Polignac number, because 1912105418521 - 2¹ = 1912105418519 is a prime.

It is a super-2 number, since 2×1912105418521² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1912105418221) 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, 239218501 + ... + 239226493.

Almost surely, 2^{1912105418521} is an apocalyptic number.

1912105418521 is the 1382789-th square number.

1912105418521 is the 691395-th centered octagonal number.

It is an amenable number.

1912105418521 is a deficient number, since it is larger than the sum of its proper divisors (11357163908).

1912105418521 is an frugal number, since it uses more digits than its factorization.

1912105418521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16332 (or 8166 counting only the distinct ones).

The product of its (nonzero) digits is 28800, while the sum is 40.

The spelling of 1912105418521 in words is "one trillion, nine hundred twelve billion, one hundred five million, four hundred eighteen thousand, five hundred twenty-one".