406139391 has 18 divisors (see below), whose sum is σ = 682425432. Its totient is φ = 232079400.

The previous prime is 406139389. The next prime is 406139411. The reversal of 406139391 is 193931604.

406139391 is a `hidden beast` number, since 4 + 0 + 613 + 9 + 39 + 1 = 666.

It is not a de Polignac number, because 406139391 - 2¹ = 406139389 is a prime.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (406139351) 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 17 ways as a sum of consecutive naturals, for example, 460035 + ... + 460916.

It is an arithmetic number, because the mean of its divisors is an integer number (37912524).

Almost surely, 2^406139391 is an apocalyptic number.

406139391 is a deficient number, since it is larger than the sum of its proper divisors (276286041).

406139391 is a wasteful number, since it uses less digits than its factorization.

406139391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 920971 (or 920961 counting only the distinct ones).

The product of its (nonzero) digits is 17496, while the sum is 36.

The square root of 406139391 is about 20152.9003123620. The cubic root of 406139391 is about 740.5567948514.

The spelling of 406139391 in words is "four hundred six million, one hundred thirty-nine thousand, three hundred ninety-one".