100121989 has 4 divisors (see below), whose sum is σ = 109224000. Its totient is φ = 91019980.

The previous prime is 100121981. The next prime is 100122023. The reversal of 100121989 is 989121001.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 100121989 - 2³ = 100121981 is a prime.

It is a super-2 number, since 2×100121989² = 20048825362632242, 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 100121989.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (100121981) 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, 4550989 + ... + 4551010.

It is an arithmetic number, because the mean of its divisors is an integer number (27306000).

Almost surely, 2^100121989 is an apocalyptic number.

It is an amenable number.

100121989 is a deficient number, since it is larger than the sum of its proper divisors (9102011).

100121989 is an equidigital number, since it uses as much as digits as its factorization.

100121989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9102010.

The product of its (nonzero) digits is 1296, while the sum is 31.

The square root of 100121989 is about 10006.0975909692. The cubic root of 100121989 is about 464.3475475923.

The spelling of 100121989 in words is "one hundred million, one hundred twenty-one thousand, nine hundred eighty-nine".