126981909 has 12 divisors (see below), whose sum is σ = 184008396. Its totient is φ = 84382272.

The previous prime is 126981893. The next prime is 126981913. The reversal of 126981909 is 909189621.

It can be written as a sum of positive squares in 2 ways, for example, as 25979409 + 101002500 = 5097^2 + 10050^2 .

It is not a de Polignac number, because 126981909 - 2⁴ = 126981893 is a prime.

It is a super-2 number, since 2×126981909² = 32248810426568562, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (126981979) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 19722 + ... + 25355.

It is an arithmetic number, because the mean of its divisors is an integer number (15334033).

Almost surely, 2^126981909 is an apocalyptic number.

It is an amenable number.

126981909 is a deficient number, since it is larger than the sum of its proper divisors (57026487).

126981909 is a wasteful number, since it uses less digits than its factorization.

126981909 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45396 (or 45393 counting only the distinct ones).

The product of its (nonzero) digits is 69984, while the sum is 45.

The square root of 126981909 is about 11268.6249826676. The cubic root of 126981909 is about 502.6287009763.

The spelling of 126981909 in words is "one hundred twenty-six million, nine hundred eighty-one thousand, nine hundred nine".