7821900440641 has 4 divisors (see below), whose sum is σ = 8939314789312. Its totient is φ = 6704486091972.

The previous prime is 7821900440597. The next prime is 7821900440671. The reversal of 7821900440641 is 1460440091287.

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 7821900440641 - 2¹⁷ = 7821900309569 is a prime.

It is a super-2 number, since 2×7821900440641² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 7821900440591 and 7821900440600.

It is not an unprimeable number, because it can be changed into a prime (7821900440671) 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, 558707174325 + ... + 558707174338.

It is an arithmetic number, because the mean of its divisors is an integer number (2234828697328).

Almost surely, 2^{7821900440641} is an apocalyptic number.

It is an amenable number.

7821900440641 is a deficient number, since it is larger than the sum of its proper divisors (1117414348671).

7821900440641 is a wasteful number, since it uses less digits than its factorization.

7821900440641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1117414348670.

The product of its (nonzero) digits is 387072, while the sum is 46.

The spelling of 7821900440641 in words is "seven trillion, eight hundred twenty-one billion, nine hundred million, four hundred forty thousand, six hundred forty-one".