101989645 has 4 divisors (see below), whose sum is σ = 122387580. Its totient is φ = 81591712.

The previous prime is 101989637. The next prime is 101989661. The reversal of 101989645 is 546989101.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 546989101 = 293 ⋅1866857.

It can be written as a sum of positive squares in 2 ways, for example, as 45724644 + 56265001 = 6762^2 + 7501^2 .

It is a cyclic number.

It is not a de Polignac number, because 101989645 - 2³ = 101989637 is a prime.

It is a super-3 number, since 3×101989645³ (a number of 25 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10198960 + ... + 10198969.

It is an arithmetic number, because the mean of its divisors is an integer number (30596895).

Almost surely, 2^101989645 is an apocalyptic number.

It is an amenable number.

101989645 is a deficient number, since it is larger than the sum of its proper divisors (20397935).

101989645 is an equidigital number, since it uses as much as digits as its factorization.

101989645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20397934.

The product of its (nonzero) digits is 77760, while the sum is 43.

The square root of 101989645 is about 10098.9922764601. The cubic root of 101989645 is about 467.2170612011.

The spelling of 101989645 in words is "one hundred one million, nine hundred eighty-nine thousand, six hundred forty-five".