126031021 has 4 divisors (see below), whose sum is σ = 128167200. Its totient is φ = 123894844.

The previous prime is 126030977. The next prime is 126031049. The reversal of 126031021 is 120130621.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 120130621 = 13 ⋅9240817.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-126031021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 126030986 and 126031004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (126032021) 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 3 ways as a sum of consecutive naturals, for example, 1068001 + ... + 1068118.

It is an arithmetic number, because the mean of its divisors is an integer number (32041800).

Almost surely, 2^126031021 is an apocalyptic number.

It is an amenable number.

126031021 is a deficient number, since it is larger than the sum of its proper divisors (2136179).

126031021 is an equidigital number, since it uses as much as digits as its factorization.

126031021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2136178.

The product of its (nonzero) digits is 72, while the sum is 16.

The square root of 126031021 is about 11226.3538604482. The cubic root of 126031021 is about 501.3709323203.

Adding to 126031021 its reverse (120130621), we get a palindrome (246161642).

The spelling of 126031021 in words is "one hundred twenty-six million, thirty-one thousand, twenty-one".