2171901 has 4 divisors (see below), whose sum is σ = 2895872. Its totient is φ = 1447932.

The previous prime is 2171899. The next prime is 2171929. The reversal of 2171901 is 1091712.

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 not a de Polignac number, because 2171901 - 2¹ = 2171899 is a prime.

It is a D-number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2171941) 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, 361981 + ... + 361986.

It is an arithmetic number, because the mean of its divisors is an integer number (723968).

2^2171901 is an apocalyptic number.

It is an amenable number.

2171901 is a deficient number, since it is larger than the sum of its proper divisors (723971).

2171901 is an equidigital number, since it uses as much as digits as its factorization.

2171901 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 723970.

The product of its (nonzero) digits is 126, while the sum is 21.

The square root of 2171901 is about 1473.7370864574. The cubic root of 2171901 is about 129.5030534504.

The spelling of 2171901 in words is "two million, one hundred seventy-one thousand, nine hundred one".