100193781 has 16 divisors (see below), whose sum is σ = 137054720. Its totient is φ = 65085120.

The previous prime is 100193777. The next prime is 100193809. The reversal of 100193781 is 187391001.

It is not a de Polignac number, because 100193781 - 2² = 100193777 is a prime.

It is a super-2 number, since 2×100193781² = 20077587502151922, which contains 22 as substring.

It is a Smith number, since the sum of its digits (30) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (100193761) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17436 + ... + 22458.

It is an arithmetic number, because the mean of its divisors is an integer number (8565920).

Almost surely, 2^100193781 is an apocalyptic number.

It is an amenable number.

100193781 is a deficient number, since it is larger than the sum of its proper divisors (36860939).

100193781 is a wasteful number, since it uses less digits than its factorization.

100193781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5196.

The product of its (nonzero) digits is 1512, while the sum is 30.

The square root of 100193781 is about 10009.6843606579. The cubic root of 100193781 is about 464.4585071485.

The spelling of 100193781 in words is "one hundred million, one hundred ninety-three thousand, seven hundred eighty-one".