84138432391 has 4 divisors (see below), whose sum is σ = 90610619512. Its totient is φ = 77666245272.

The previous prime is 84138432383. The next prime is 84138432397. The reversal of 84138432391 is 19323483148.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 84138432391 - 2³ = 84138432383 is a prime.

It is a super-6 number, since 6×84138432391⁶ (a number of 67 digits) contains 666666 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (84138432397) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3236093541 + ... + 3236093566.

It is an arithmetic number, because the mean of its divisors is an integer number (22652654878).

Almost surely, 2^84138432391 is an apocalyptic number.

84138432391 is a deficient number, since it is larger than the sum of its proper divisors (6472187121).

84138432391 is a wasteful number, since it uses less digits than its factorization.

84138432391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6472187120.

The product of its digits is 497664, while the sum is 46.

The spelling of 84138432391 in words is "eighty-four billion, one hundred thirty-eight million, four hundred thirty-two thousand, three hundred ninety-one".