2191654620 has 108 divisors (see below), whose sum is σ = 7062250104. Its totient is φ = 550049280.

The previous prime is 2191654601. The next prime is 2191654639. The reversal of 2191654620 is 264561912.

2191654620 is a `hidden beast` number, since 2 + 1 + 91 + 6 + 546 + 20 = 666.

It is an interprime number because it is at equal distance from previous prime (2191654601) and next prime (2191654639).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 30955 + ... + 73085.

Almost surely, 2^2191654620 is an apocalyptic number.

2191654620 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 2191654620, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3531125052).

2191654620 is an abundant number, since it is smaller than the sum of its proper divisors (4870595484).

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

2191654620 is a wasteful number, since it uses less digits than its factorization.

2191654620 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42180 (or 42158 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 36.

The square root of 2191654620 is about 46815.1110219767. Note that the first 3 decimals coincide. The cubic root of 2191654620 is about 1298.9448281979.

The spelling of 2191654620 in words is "two billion, one hundred ninety-one million, six hundred fifty-four thousand, six hundred twenty".