100661321 has 4 divisors (see below), whose sum is σ = 101874192. Its totient is φ = 99448452.

The previous prime is 100661311. The next prime is 100661329. The reversal of 100661321 is 123166001.

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, and also an emirpimes, since its reverse is a distinct semiprime: 123166001 = 7 ⋅17595143.

It is a cyclic number.

It is not a de Polignac number, because 100661321 - 2¹⁰ = 100660297 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 100661293 and 100661302.

It is not an unprimeable number, because it can be changed into a prime (100661329) 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, 606311 + ... + 606476.

It is an arithmetic number, because the mean of its divisors is an integer number (25468548).

Almost surely, 2^100661321 is an apocalyptic number.

It is an amenable number.

100661321 is a deficient number, since it is larger than the sum of its proper divisors (1212871).

100661321 is an equidigital number, since it uses as much as digits as its factorization.

100661321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1212870.

The product of its (nonzero) digits is 216, while the sum is 20.

The square root of 100661321 is about 10033.0115618392. The cubic root of 100661321 is about 465.1798294705.

The spelling of 100661321 in words is "one hundred million, six hundred sixty-one thousand, three hundred twenty-one".