127905654321 has 27 divisors (see below), whose sum is σ = 186828930561. Its totient is φ = 84322692864.

The previous prime is 127905654313. The next prime is 127905654397. The reversal of 127905654321 is 123456509721.

The square root of 127905654321 is 357639.

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

127905654321 is a `hidden beast` number, since 1 + 27 + 9 + 0 + 565 + 43 + 21 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 43203701025 + 84701953296 = 207855^2 + 291036^2 .

It is not a de Polignac number, because 127905654321 - 2³ = 127905654313 is a prime.

It is not an unprimeable number, because it can be changed into a prime (127905654311) 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, 104072335 + ... + 104073563.

Almost surely, 2^127905654321 is an apocalyptic number.

127905654321 is the 357639-th square number.

127905654321 is the 178820-th centered octagonal number.

It is an amenable number.

127905654321 is a deficient number, since it is larger than the sum of its proper divisors (58923276240).

127905654321 is an frugal number, since it uses more digits than its factorization.

127905654321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2658 (or 1329 counting only the distinct ones).

The product of its (nonzero) digits is 453600, while the sum is 45.

The spelling of 127905654321 in words is "one hundred twenty-seven billion, nine hundred five million, six hundred fifty-four thousand, three hundred twenty-one".