100549891 has 4 divisors (see below), whose sum is σ = 108284512. Its totient is φ = 92815272.

The previous prime is 100549861. The next prime is 100549901. The reversal of 100549891 is 198945001.

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 100549891 - 2⁷ = 100549763 is a prime.

It is a super-2 number, since 2×100549891² = 20220561160223762, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 100549891.

It is not an unprimeable number, because it can be changed into a prime (100549811) 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, 3867291 + ... + 3867316.

It is an arithmetic number, because the mean of its divisors is an integer number (27071128).

Almost surely, 2^100549891 is an apocalyptic number.

100549891 is a deficient number, since it is larger than the sum of its proper divisors (7734621).

100549891 is an equidigital number, since it uses as much as digits as its factorization.

100549891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7734620.

The product of its (nonzero) digits is 12960, while the sum is 37.

The square root of 100549891 is about 10027.4568560528. The cubic root of 100549891 is about 465.0081179451.

The spelling of 100549891 in words is "one hundred million, five hundred forty-nine thousand, eight hundred ninety-one".