126670021 has 4 divisors (see below), whose sum is σ = 127238272. Its totient is φ = 126101772.

The previous prime is 126670013. The next prime is 126670031. The reversal of 126670021 is 120076621.

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: 120076621 = 7 ⋅17153803.

It is a cyclic number.

It is not a de Polignac number, because 126670021 - 2³ = 126670013 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (126670031) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 283791 + ... + 284236.

It is an arithmetic number, because the mean of its divisors is an integer number (31809568).

Almost surely, 2^126670021 is an apocalyptic number.

It is an amenable number.

126670021 is a deficient number, since it is larger than the sum of its proper divisors (568251).

126670021 is an equidigital number, since it uses as much as digits as its factorization.

126670021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 568250.

The product of its (nonzero) digits is 1008, while the sum is 25.

The square root of 126670021 is about 11254.7776966051. Note that the first 3 decimals coincide. The cubic root of 126670021 is about 502.2168512814.

The spelling of 126670021 in words is "one hundred twenty-six million, six hundred seventy thousand, twenty-one".