2124851821 has 4 divisors (see below), whose sum is σ = 2125574332. Its totient is φ = 2124129312.

The previous prime is 2124851809. The next prime is 2124851867. The reversal of 2124851821 is 1281584212.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1431108900 + 693742921 = 37830^2 + 26339^2 .

It is a cyclic number.

It is not a de Polignac number, because 2124851821 - 2⁵ = 2124851789 is a prime.

It is a super-2 number, since 2×2124851821² = 9029990522414032082, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2124851801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 356826 + ... + 362731.

It is an arithmetic number, because the mean of its divisors is an integer number (531393583).

Almost surely, 2^2124851821 is an apocalyptic number.

It is an amenable number.

2124851821 is a deficient number, since it is larger than the sum of its proper divisors (722511).

2124851821 is an equidigital number, since it uses as much as digits as its factorization.

2124851821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 722510.

The product of its digits is 10240, while the sum is 34.

The square root of 2124851821 is about 46096.1150315295. The cubic root of 2124851821 is about 1285.6109115024.

The spelling of 2124851821 in words is "two billion, one hundred twenty-four million, eight hundred fifty-one thousand, eight hundred twenty-one".