105287921 has 4 divisors (see below), whose sum is σ = 105985344. Its totient is φ = 104590500.

The previous prime is 105287867. The next prime is 105287929. The reversal of 105287921 is 129782501.

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 105287921 - 2⁶ = 105287857 is a prime.

It is a super-2 number, since 2×105287921² = 22171092617004482, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (105287929) 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, 348485 + ... + 348786.

It is an arithmetic number, because the mean of its divisors is an integer number (26496336).

Almost surely, 2^105287921 is an apocalyptic number.

It is an amenable number.

105287921 is a deficient number, since it is larger than the sum of its proper divisors (697423).

105287921 is an equidigital number, since it uses as much as digits as its factorization.

105287921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 697422.

The product of its (nonzero) digits is 10080, while the sum is 35.

The square root of 105287921 is about 10260.9902543565. The cubic root of 105287921 is about 472.2002181909.

The spelling of 105287921 in words is "one hundred five million, two hundred eighty-seven thousand, nine hundred twenty-one".