126821391 has 16 divisors (see below), whose sum is σ = 171256800. Its totient is φ = 83472768.

The previous prime is 126821381. The next prime is 126821399. The reversal of 126821391 is 193128621.

It is not a de Polignac number, because 126821391 - 2⁶ = 126821327 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (126821399) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 126705 + ... + 127701.

It is an arithmetic number, because the mean of its divisors is an integer number (10703550).

Almost surely, 2^126821391 is an apocalyptic number.

126821391 is a deficient number, since it is larger than the sum of its proper divisors (44435409).

126821391 is a wasteful number, since it uses less digits than its factorization.

126821391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1498.

The product of its digits is 5184, while the sum is 33.

The square root of 126821391 is about 11261.5003884918. The cubic root of 126821391 is about 502.4168204687.

The spelling of 126821391 in words is "one hundred twenty-six million, eight hundred twenty-one thousand, three hundred ninety-one".