9999999431 has 4 divisors (see below), whose sum is σ = 10078739712. Its totient is φ = 9921259152.

The previous prime is 9999999379. The next prime is 9999999479. The reversal of 9999999431 is 1349999999.

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 9999999431 - 2⁶ = 9999999367 is a prime.

It is a super-2 number, since 2×9999999431² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a nialpdrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9999999491) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 39369950 + ... + 39370203.

It is an arithmetic number, because the mean of its divisors is an integer number (2519684928).

Almost surely, 2^9999999431 is an apocalyptic number.

9999999431 is a deficient number, since it is larger than the sum of its proper divisors (78740281).

9999999431 is a wasteful number, since it uses less digits than its factorization.

9999999431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78740280.

The product of its digits is 57395628, while the sum is 71.

The square root of 9999999431 is about 99999.9971550000. The cubic root of 9999999431 is about 2154.4346491694.

The spelling of 9999999431 in words is "nine billion, nine hundred ninety-nine million, nine hundred ninety-nine thousand, four hundred thirty-one".