2190171661 has 4 divisors (see below), whose sum is σ = 2243590524. Its totient is φ = 2136752800.

The previous prime is 2190171649. The next prime is 2190171671. The reversal of 2190171661 is 1661710912.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 821911561 + 1368260100 = 28669^2 + 36990^2 .

It is a cyclic number.

It is not a de Polignac number, because 2190171661 - 2¹⁹ = 2189647373 is a prime.

It is a super-3 number, since 3×2190171661³ (a number of 29 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2190171601) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26709370 + ... + 26709451.

It is an arithmetic number, because the mean of its divisors is an integer number (560897631).

Almost surely, 2^2190171661 is an apocalyptic number.

It is an amenable number.

2190171661 is a deficient number, since it is larger than the sum of its proper divisors (53418863).

2190171661 is an equidigital number, since it uses as much as digits as its factorization.

2190171661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53418862.

The product of its (nonzero) digits is 4536, while the sum is 34.

The square root of 2190171661 is about 46799.2698767833. The cubic root of 2190171661 is about 1298.6517898492.

The spelling of 2190171661 in words is "two billion, one hundred ninety million, one hundred seventy-one thousand, six hundred sixty-one".