2121240 has 64 divisors (see below), whose sum is σ = 6946560. Its totient is φ = 513920.

The previous prime is 2121239. The next prime is 2121241. The reversal of 2121240 is 421212.

It is an interprime number because it is at equal distance from previous prime (2121239) and next prime (2121241).

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2121241) 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, 517 + ... + 2123.

It is an arithmetic number, because the mean of its divisors is an integer number (108540).

2^2121240 is an apocalyptic number.

2121240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2121240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3473280).

2121240 is an abundant number, since it is smaller than the sum of its proper divisors (4825320).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

2121240 is a wasteful number, since it uses less digits than its factorization.

2121240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1632 (or 1628 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 12.

The square root of 2121240 is about 1456.4477333567. The cubic root of 2121240 is about 128.4882071672.

Adding to 2121240 its reverse (421212), we get a palindrome (2542452).

It can be divided in two parts, 21 and 21240, that multiplied together give a triangular number (446040 = T₉₄₄).

The spelling of 2121240 in words is "two million, one hundred twenty-one thousand, two hundred forty".