3126821861 has 4 divisors (see below), whose sum is σ = 3173490912. Its totient is φ = 3080152812.

The previous prime is 3126821809. The next prime is 3126821881. The reversal of 3126821861 is 1681286213.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 3126821861 - 2³⁰ = 2053080037 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3126821881) 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, 23334425 + ... + 23334558.

It is an arithmetic number, because the mean of its divisors is an integer number (793372728).

Almost surely, 2^3126821861 is an apocalyptic number.

It is an amenable number.

3126821861 is a deficient number, since it is larger than the sum of its proper divisors (46669051).

3126821861 is an equidigital number, since it uses as much as digits as its factorization.

3126821861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46669050.

The product of its digits is 27648, while the sum is 38.

The square root of 3126821861 is about 55917.9922833429. The cubic root of 3126821861 is about 1462.2929287854.

The spelling of 3126821861 in words is "three billion, one hundred twenty-six million, eight hundred twenty-one thousand, eight hundred sixty-one".