2154921 has 16 divisors (see below), whose sum is σ = 2976768. Its totient is φ = 1386000.

The previous prime is 2154913. The next prime is 2154931. The reversal of 2154921 is 1294512.

It is not a de Polignac number, because 2154921 - 2³ = 2154913 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 2154891 and 2154900.

It is not an unprimeable number, because it can be changed into a prime (2154931) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14196 + ... + 14346.

It is an arithmetic number, because the mean of its divisors is an integer number (186048).

2^2154921 is an apocalyptic number.

It is an amenable number.

2154921 is a deficient number, since it is larger than the sum of its proper divisors (821847).

2154921 is a wasteful number, since it uses less digits than its factorization.

2154921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 292.

The product of its digits is 720, while the sum is 24.

The square root of 2154921 is about 1467.9649178369. The cubic root of 2154921 is about 129.1646836093.

The spelling of 2154921 in words is "two million, one hundred fifty-four thousand, nine hundred twenty-one".