2544394981 has 4 divisors (see below), whose sum is σ = 2694065292. Its totient is φ = 2394724672.

The previous prime is 2544394969. The next prime is 2544394991. The reversal of 2544394981 is 1894934452.

It is a happy number.

2544394981 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1464286756 + 1080108225 = 38266^2 + 32865^2 .

It is a cyclic number.

It is not a de Polignac number, because 2544394981 - 2²⁹ = 2007524069 is a prime.

It is a super-2 number, since 2×2544394981² = 12947891638675980722, which contains 22 as substring.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2544394921) 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, 74835130 + ... + 74835163.

It is an arithmetic number, because the mean of its divisors is an integer number (673516323).

Almost surely, 2^2544394981 is an apocalyptic number.

It is an amenable number.

2544394981 is a deficient number, since it is larger than the sum of its proper divisors (149670311).

2544394981 is a wasteful number, since it uses less digits than its factorization.

2544394981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 149670310.

The product of its digits is 1244160, while the sum is 49.

The square root of 2544394981 is about 50441.9962035604. The cubic root of 2544394981 is about 1365.1954853375.

The spelling of 2544394981 in words is "two billion, five hundred forty-four million, three hundred ninety-four thousand, nine hundred eighty-one".