126522721 has 16 divisors (see below), whose sum is σ = 148179024. Its totient is φ = 106942464.

The previous prime is 126522677. The next prime is 126522787. The reversal of 126522721 is 127225621.

It can be written as a sum of positive squares in 8 ways, for example, as 2512225 + 124010496 = 1585^2 + 11136^2 .

It is a cyclic number.

It is not a de Polignac number, because 126522721 - 2⁷ = 126522593 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 126522721.

It is not an unprimeable number, because it can be changed into a prime (126523721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 441 + ... + 15913.

It is an arithmetic number, because the mean of its divisors is an integer number (9261189).

Almost surely, 2^126522721 is an apocalyptic number.

It is an amenable number.

126522721 is a deficient number, since it is larger than the sum of its proper divisors (21656303).

126522721 is a wasteful number, since it uses less digits than its factorization.

126522721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15540.

The product of its digits is 3360, while the sum is 28.

The square root of 126522721 is about 11248.2319055041. The cubic root of 126522721 is about 502.0221058185.

The spelling of 126522721 in words is "one hundred twenty-six million, five hundred twenty-two thousand, seven hundred twenty-one".