7859437921 has 4 divisors (see below), whose sum is σ = 7904868372. Its totient is φ = 7814007472.

The previous prime is 7859437891. The next prime is 7859437979. The reversal of 7859437921 is 1297349587.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1297349587 = 4289 ⋅302483.

It can be written as a sum of positive squares in 2 ways, for example, as 7562737296 + 296700625 = 86964^2 + 17225^2 .

It is a cyclic number.

It is not a de Polignac number, because 7859437921 - 2⁵ = 7859437889 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (7859437021) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22714966 + ... + 22715311.

It is an arithmetic number, because the mean of its divisors is an integer number (1976217093).

Almost surely, 2^7859437921 is an apocalyptic number.

It is an amenable number.

7859437921 is a deficient number, since it is larger than the sum of its proper divisors (45430451).

7859437921 is a wasteful number, since it uses less digits than its factorization.

7859437921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45430450.

The product of its digits is 3810240, while the sum is 55.

The square root of 7859437921 is about 88653.4710036781. The cubic root of 7859437921 is about 1988.2172126994.

The spelling of 7859437921 in words is "seven billion, eight hundred fifty-nine million, four hundred thirty-seven thousand, nine hundred twenty-one".