2061651997 has 4 divisors (see below), whose sum is σ = 2065463356. Its totient is φ = 2057840640.

The previous prime is 2061651983. The next prime is 2061652007. The reversal of 2061651997 is 7991561602.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7991561602 = 2 ⋅3995780801.

It can be written as a sum of positive squares in 2 ways, for example, as 375235641 + 1686416356 = 19371^2 + 41066^2 .

It is a cyclic number.

It is not a de Polignac number, because 2061651997 - 2¹¹ = 2061649949 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2061651967) 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, 1904868 + ... + 1905949.

It is an arithmetic number, because the mean of its divisors is an integer number (516365839).

Almost surely, 2^2061651997 is an apocalyptic number.

It is an amenable number.

2061651997 is a deficient number, since it is larger than the sum of its proper divisors (3811359).

2061651997 is an equidigital number, since it uses as much as digits as its factorization.

2061651997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3811358.

The product of its (nonzero) digits is 204120, while the sum is 46.

The square root of 2061651997 is about 45405.4181458557. The cubic root of 2061651997 is about 1272.7363648094.

The spelling of 2061651997 in words is "two billion, sixty-one million, six hundred fifty-one thousand, nine hundred ninety-seven".