100043391 has 8 divisors (see below), whose sum is σ = 152447104. Its totient is φ = 57167640.

The previous prime is 100043371. The next prime is 100043393. The reversal of 100043391 is 193340001.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 100043391 - 2⁷ = 100043263 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21), and also a Moran number because the ratio is a prime number: 4763971 = 100043391 / (1 + 0 + 0 + 0 + 4 + 3 + 3 + 9 + 1).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (100043393) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2381965 + ... + 2382006.

It is an arithmetic number, because the mean of its divisors is an integer number (19055888).

Almost surely, 2^100043391 is an apocalyptic number.

100043391 is a deficient number, since it is larger than the sum of its proper divisors (52403713).

100043391 is an equidigital number, since it uses as much as digits as its factorization.

100043391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4763981.

The product of its (nonzero) digits is 324, while the sum is 21.

The square root of 100043391 is about 10002.1693147037. The cubic root of 100043391 is about 464.2260080472.

Adding to 100043391 its reverse (193340001), we get a palindrome (293383392).

The spelling of 100043391 in words is "one hundred million, forty-three thousand, three hundred ninety-one".