2251746781 has 4 divisors (see below), whose sum is σ = 2384202492. Its totient is φ = 2119291072.

The previous prime is 2251746779. The next prime is 2251746793. The reversal of 2251746781 is 1876471522.

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 2037709881 + 214036900 = 45141^2 + 14630^2 .

It is a cyclic number.

It is not a de Polignac number, because 2251746781 - 2¹ = 2251746779 is a prime.

It is a super-2 number, since 2×2251746781² = 10140727131487723922, 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 (2251746701) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 66227830 + ... + 66227863.

It is an arithmetic number, because the mean of its divisors is an integer number (596050623).

Almost surely, 2^2251746781 is an apocalyptic number.

It is an amenable number.

2251746781 is a deficient number, since it is larger than the sum of its proper divisors (132455711).

2251746781 is a wasteful number, since it uses less digits than its factorization.

2251746781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 132455710.

The product of its digits is 188160, while the sum is 43.

The square root of 2251746781 is about 47452.5740186979. The cubic root of 2251746781 is about 1310.7097102240.

The spelling of 2251746781 in words is "two billion, two hundred fifty-one million, seven hundred forty-six thousand, seven hundred eighty-one".