127869892921 has 9 divisors (see below), whose sum is σ = 128359869229. Its totient is φ = 127381783936.

The previous prime is 127869892907. The next prime is 127869892951. The reversal of 127869892921 is 129298968721.

The square root of 127869892921 is 357589.

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 70298689321 + 57571203600 = 265139^2 + 239940^2 .

It is not a de Polignac number, because 127869892921 - 2¹¹ = 127869890873 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (127869892951) 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, 126228411 + ... + 126229423.

Almost surely, 2^127869892921 is an apocalyptic number.

127869892921 is the 357589-th square number.

127869892921 is the 178795-th centered octagonal number.

It is an amenable number.

127869892921 is a deficient number, since it is larger than the sum of its proper divisors (489976308).

127869892921 is an frugal number, since it uses more digits than its factorization.

127869892921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2732 (or 1366 counting only the distinct ones).

The product of its digits is 15676416, while the sum is 64.

Multiplying 127869892921 by its sum of digits (64), we get a square (8183673146944 = 2860712²).

The spelling of 127869892921 in words is "one hundred twenty-seven billion, eight hundred sixty-nine million, eight hundred ninety-two thousand, nine hundred twenty-one".