2151688 has 48 divisors (see below), whose sum is σ = 5130000. Its totient is φ = 836640.

The previous prime is 2151683. The next prime is 2151701. The reversal of 2151688 is 8861512.

It is a super-2 number, since 2×2151688² = 9259522498688, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (2151683) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4063 + ... + 4561.

It is an arithmetic number, because the mean of its divisors is an integer number (106875).

2^2151688 is an apocalyptic number.

2151688 is a gapful number since it is divisible by the number (28) 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 2151688, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2565000).

2151688 is an abundant number, since it is smaller than the sum of its proper divisors (2978312).

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

2151688 is a wasteful number, since it uses less digits than its factorization.

2151688 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 530 (or 519 counting only the distinct ones).

The product of its digits is 3840, while the sum is 31.

The square root of 2151688 is about 1466.8633201495. The cubic root of 2151688 is about 129.1000565795.

It can be divided in two parts, 215168 and 8, that multiplied together give a square (1721344 = 1312²).

The spelling of 2151688 in words is "two million, one hundred fifty-one thousand, six hundred eighty-eight".