285878401227721 has 3 divisors (see below), whose sum is σ = 285878418135661. Its totient is φ = 285878384319782.

The previous prime is 285878401227709. The next prime is 285878401227751. The reversal of 285878401227721 is 127722104878582.

The square root of 285878401227721 is 16907939.

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

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is not a de Polignac number, because 285878401227721 - 2³¹ = 285876253744073 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (285878401227751) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 8453970 + ... + 25361908.

Almost surely, 2^{285878401227721} is an apocalyptic number.

285878401227721 is the 16907939-th square number.

285878401227721 is the 8453970-th centered octagonal number.

It is an amenable number.

285878401227721 is a deficient number, since it is larger than the sum of its proper divisors (16907940).

285878401227721 is an frugal number, since it uses more digits than its factorization.

285878401227721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33815878 (or 16907939 counting only the distinct ones).

The product of its (nonzero) digits is 56197120, while the sum is 64.

The spelling of 285878401227721 in words is "two hundred eighty-five trillion, eight hundred seventy-eight billion, four hundred one million, two hundred twenty-seven thousand, seven hundred twenty-one".