126401391 has 10 divisors (see below), whose sum is σ = 188821952. Its totient is φ = 84267540.

The previous prime is 126401323. The next prime is 126401393. The reversal of 126401391 is 193104621.

126401391 is a `hidden beast` number, since 1 + 2 + 640 + 13 + 9 + 1 = 666.

It is not a de Polignac number, because 126401391 - 2⁷ = 126401263 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (126401393) 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 9 ways as a sum of consecutive naturals, for example, 780175 + ... + 780336.

Almost surely, 2^126401391 is an apocalyptic number.

126401391 is a deficient number, since it is larger than the sum of its proper divisors (62420561).

126401391 is an equidigital number, since it uses as much as digits as its factorization.

126401391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1560523 (or 1560514 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 27.

The square root of 126401391 is about 11242.8373198228. The cubic root of 126401391 is about 501.8615817583.

The spelling of 126401391 in words is "one hundred twenty-six million, four hundred one thousand, three hundred ninety-one".