2678804091581 has 4 divisors (see below), whose sum is σ = 2699897037312. Its totient is φ = 2657711145852.

The previous prime is 2678804091577. The next prime is 2678804091617. The reversal of 2678804091581 is 1851904088762.

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 2678804091581 - 2² = 2678804091577 is a prime.

It is a super-2 number, since 2×2678804091581² (a number of 26 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2678804091581.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2678804096581) 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, 10546472675 + ... + 10546472928.

It is an arithmetic number, because the mean of its divisors is an integer number (674974259328).

Almost surely, 2^{2678804091581} is an apocalyptic number.

It is an amenable number.

2678804091581 is a deficient number, since it is larger than the sum of its proper divisors (21092945731).

2678804091581 is a wasteful number, since it uses less digits than its factorization.

2678804091581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21092945730.

The product of its (nonzero) digits is 7741440, while the sum is 59.

The spelling of 2678804091581 in words is "two trillion, six hundred seventy-eight billion, eight hundred four million, ninety-one thousand, five hundred eighty-one".