7841861021 has 4 divisors (see below), whose sum is σ = 7842859200. Its totient is φ = 7840862844.

The previous prime is 7841861009. The next prime is 7841861033. The reversal of 7841861021 is 1201681487.

It is a happy number.

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, and also an emirpimes, since its reverse is a distinct semiprime: 1201681487 = 7079 ⋅169753.

It is an interprime number because it is at equal distance from previous prime (7841861009) and next prime (7841861033).

It is a cyclic number.

It is not a de Polignac number, because 7841861021 - 2²⁶ = 7774752157 is a prime.

It is a super-2 number, since 2×7841861021² (a number of 21 digits) 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 (7841861081) 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, 487211 + ... + 503048.

It is an arithmetic number, because the mean of its divisors is an integer number (1960714800).

Almost surely, 2^7841861021 is an apocalyptic number.

It is an amenable number.

7841861021 is a deficient number, since it is larger than the sum of its proper divisors (998179).

7841861021 is an equidigital number, since it uses as much as digits as its factorization.

7841861021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 998178.

The product of its (nonzero) digits is 21504, while the sum is 38.

The square root of 7841861021 is about 88554.2829060232. The cubic root of 7841861021 is about 1986.7339522946.

The spelling of 7841861021 in words is "seven billion, eight hundred forty-one million, eight hundred sixty-one thousand, twenty-one".