126778013 has 4 divisors (see below), whose sum is σ = 133450560. Its totient is φ = 120105468.

The previous prime is 126777997. The next prime is 126778031. The reversal of 126778013 is 310877621.

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: 310877621 = 41 ⋅7582381.

It is a cyclic number.

It is not a de Polignac number, because 126778013 - 2⁴ = 126777997 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 (126778073) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3336245 + ... + 3336282.

It is an arithmetic number, because the mean of its divisors is an integer number (33362640).

Almost surely, 2^126778013 is an apocalyptic number.

It is an amenable number.

126778013 is a deficient number, since it is larger than the sum of its proper divisors (6672547).

126778013 is an equidigital number, since it uses as much as digits as its factorization.

126778013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6672546.

The product of its (nonzero) digits is 14112, while the sum is 35.

The square root of 126778013 is about 11259.5742814726. The cubic root of 126778013 is about 502.3595317050.

The spelling of 126778013 in words is "one hundred twenty-six million, seven hundred seventy-eight thousand, thirteen".