2126718981 has 6 divisors (see below), whose sum is σ = 3071927430. Its totient is φ = 1417812648.

The previous prime is 2126718977. The next prime is 2126719003. The reversal of 2126718981 is 1898176212.

It can be written as a sum of positive squares in only one way, i.e., 2093886081 + 32832900 = 45759^2 + 5730^2 .

It is not a de Polignac number, because 2126718981 - 2² = 2126718977 is a prime.

It is a super-2 number, since 2×2126718981² = 9045867248291356722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2126718911) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 118151046 + ... + 118151063.

It is an arithmetic number, because the mean of its divisors is an integer number (511987905).

Almost surely, 2^2126718981 is an apocalyptic number.

It is an amenable number.

2126718981 is a deficient number, since it is larger than the sum of its proper divisors (945208449).

2126718981 is a wasteful number, since it uses less digits than its factorization.

2126718981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 236302115 (or 236302112 counting only the distinct ones).

The product of its digits is 96768, while the sum is 45.

The square root of 2126718981 is about 46116.3634841257. The cubic root of 2126718981 is about 1285.9873673223.

The spelling of 2126718981 in words is "two billion, one hundred twenty-six million, seven hundred eighteen thousand, nine hundred eighty-one".