2155920 has 80 divisors (see below), whose sum is σ = 7207872. Its totient is φ = 529920.

The previous prime is 2155883. The next prime is 2155931. The reversal of 2155920 is 295512.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2775 + ... + 3465.

2^2155920 is an apocalyptic number.

2155920 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 2155920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3603936).

2155920 is an abundant number, since it is smaller than the sum of its proper divisors (5051952).

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

2155920 is a wasteful number, since it uses less digits than its factorization.

2155920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 720 (or 714 counting only the distinct ones).

The product of its (nonzero) digits is 900, while the sum is 24.

The square root of 2155920 is about 1468.3051453972. The cubic root of 2155920 is about 129.1846403477.

The spelling of 2155920 in words is "two million, one hundred fifty-five thousand, nine hundred twenty".