27878378781 has 16 divisors (see below), whose sum is σ = 40555266048. Its totient is φ = 16893946800.

The previous prime is 27878378741. The next prime is 27878378831. The reversal of 27878378781 is 18787387872.

It is not a de Polignac number, because 27878378781 - 2¹⁰ = 27878377757 is a prime.

It is a super-2 number, since 2×27878378781² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (27878378701) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 253540 + ... + 346466.

It is an arithmetic number, because the mean of its divisors is an integer number (2534704128).

Almost surely, 2^27878378781 is an apocalyptic number.

It is an amenable number.

27878378781 is a deficient number, since it is larger than the sum of its proper divisors (12676887267).

27878378781 is a wasteful number, since it uses less digits than its factorization.

27878378781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102032.

The product of its digits is 59006976, while the sum is 66.

Subtracting from 27878378781 its reverse (18787387872), we obtain a palindrome (9090990909).

The spelling of 27878378781 in words is "twenty-seven billion, eight hundred seventy-eight million, three hundred seventy-eight thousand, seven hundred eighty-one".