126275721 has 24 divisors (see below), whose sum is σ = 199308480. Its totient is φ = 70641120.

The previous prime is 126275717. The next prime is 126275731. The reversal of 126275721 is 127572621.

It is not a de Polignac number, because 126275721 - 2² = 126275717 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (126275731) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 8661 + ... + 18098.

It is an arithmetic number, because the mean of its divisors is an integer number (8304520).

Almost surely, 2^126275721 is an apocalyptic number.

126275721 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

126275721 is a deficient number, since it is larger than the sum of its proper divisors (73032759).

126275721 is a wasteful number, since it uses less digits than its factorization.

126275721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26797 (or 26786 counting only the distinct ones).

The product of its digits is 11760, while the sum is 33.

The square root of 126275721 is about 11237.2470383097. The cubic root of 126275721 is about 501.6952073818.

The spelling of 126275721 in words is "one hundred twenty-six million, two hundred seventy-five thousand, seven hundred twenty-one".