2078148781 has 4 divisors (see below), whose sum is σ = 2078257500. Its totient is φ = 2078040064.

The previous prime is 2078148773. The next prime is 2078148791. The reversal of 2078148781 is 1878418702.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 1878418702 = 2 ⋅939209351.

It can be written as a sum of positive squares in 2 ways, for example, as 1994426281 + 83722500 = 44659^2 + 9150^2 .

It is a cyclic number.

It is not a de Polignac number, because 2078148781 - 2³ = 2078148773 is a prime.

It is a super-2 number, since 2×2078148781² = 8637404711943571922, which 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 (2078148791) 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, 17236 + ... + 66733.

It is an arithmetic number, because the mean of its divisors is an integer number (519564375).

Almost surely, 2^2078148781 is an apocalyptic number.

It is an amenable number.

2078148781 is a deficient number, since it is larger than the sum of its proper divisors (108719).

2078148781 is an equidigital number, since it uses as much as digits as its factorization.

2078148781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 108718.

The product of its (nonzero) digits is 200704, while the sum is 46.

The square root of 2078148781 is about 45586.7171553294. The cubic root of 2078148781 is about 1276.1220482260.

The spelling of 2078148781 in words is "two billion, seventy-eight million, one hundred forty-eight thousand, seven hundred eighty-one".