2161972 has 12 divisors (see below), whose sum is σ = 3982720. Its totient is φ = 1024056.

The previous prime is 2161967. The next prime is 2161987. The reversal of 2161972 is 2791612.

It is a happy number.

2161972 is digitally balanced in base 2 and base 5, because in such bases it contains all the possibile digits an equal number of times.

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 2161972.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14148 + ... + 14299.

2^2161972 is an apocalyptic number.

It is an amenable number.

2161972 is a deficient number, since it is larger than the sum of its proper divisors (1820748).

2161972 is a wasteful number, since it uses less digits than its factorization.

2161972 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28470 (or 28468 counting only the distinct ones).

The product of its digits is 1512, while the sum is 28.

The square root of 2161972 is about 1470.3645806398. The cubic root of 2161972 is about 129.3054078180.

The spelling of 2161972 in words is "two million, one hundred sixty-one thousand, nine hundred seventy-two".