1282427721 has 45 divisors (see below), whose sum is σ = 2014282039. Its totient is φ = 813052944.

The previous prime is 1282427693. The next prime is 1282427833. The reversal of 1282427721 is 1277242821.

The square root of 1282427721 is 35811.

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

It can be written as a sum of positive squares in only one way, i.e., 1166564025 + 115863696 = 34155^2 + 10764^2 .

It is not a de Polignac number, because 1282427721 - 2⁵ = 1282427689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1282427221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 7412791 + ... + 7412963.

Almost surely, 2^1282427721 is an apocalyptic number.

1282427721 is the 35811-st square number.

1282427721 is the 17906-th centered octagonal number.

It is an amenable number.

1282427721 is a deficient number, since it is larger than the sum of its proper divisors (731854318).

1282427721 is an frugal number, since it uses more digits than its factorization.

1282427721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 404 (or 199 counting only the distinct ones).

The product of its digits is 25088, while the sum is 36.

The cubic root of 1282427721 is about 1086.4530556804.

Multiplying 1282427721 by its sum of digits (36), we get a square (46167397956 = 214866²).

The spelling of 1282427721 in words is "one billion, two hundred eighty-two million, four hundred twenty-seven thousand, seven hundred twenty-one".