2147921 has 4 divisors (see below), whose sum is σ = 2156352. Its totient is φ = 2139492.

The previous prime is 2147911. The next prime is 2147923. The reversal of 2147921 is 1297412.

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 2147921 - 2¹⁰ = 2146897 is a prime.

It is a super-2 number, since 2×2147921² = 9227129244482, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2147923) 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, 3821 + ... + 4346.

It is an arithmetic number, because the mean of its divisors is an integer number (539088).

2^2147921 is an apocalyptic number.

It is an amenable number.

2147921 is a deficient number, since it is larger than the sum of its proper divisors (8431).

2147921 is an equidigital number, since it uses as much as digits as its factorization.

2147921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8430.

The product of its digits is 1008, while the sum is 26.

The square root of 2147921 is about 1465.5787252823. The cubic root of 2147921 is about 129.0246732847.

The spelling of 2147921 in words is "two million, one hundred forty-seven thousand, nine hundred twenty-one".