2128454861 has 12 divisors (see below), whose sum is σ = 2326968252. Its totient is φ = 1935350208.

The previous prime is 2128454833. The next prime is 2128454863. The reversal of 2128454861 is 1684548212.

It can be written as a sum of positive squares in 2 ways, for example, as 549902500 + 1578552361 = 23450^2 + 39731^2 .

It is not a de Polignac number, because 2128454861 - 2²² = 2124260557 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2128454863) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 40121 + ... + 76593.

It is an arithmetic number, because the mean of its divisors is an integer number (193914021).

Almost surely, 2^2128454861 is an apocalyptic number.

It is an amenable number.

2128454861 is a deficient number, since it is larger than the sum of its proper divisors (198513391).

2128454861 is an equidigital number, since it uses as much as digits as its factorization.

2128454861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36620 (or 36553 counting only the distinct ones).

The product of its digits is 122880, while the sum is 41.

The square root of 2128454861 is about 46135.1802966023. The cubic root of 2128454861 is about 1286.3371569416.

The spelling of 2128454861 in words is "two billion, one hundred twenty-eight million, four hundred fifty-four thousand, eight hundred sixty-one".