2111650721 has 2 divisors, whose sum is σ = 2111650722. Its totient is φ = 2111650720.

The previous prime is 2111650711. The next prime is 2111650741. The reversal of 2111650721 is 1270561112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1524121600 + 587529121 = 39040^2 + 24239^2 .

It is a cyclic number.

It is not a de Polignac number, because 2111650721 - 2⁶ = 2111650657 is a prime.

It is a super-3 number, since 3×2111650721³ (a number of 29 digits) contains 333 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (2111650711) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1055825360 + 1055825361.

It is an arithmetic number, because the mean of its divisors is an integer number (1055825361).

Almost surely, 2^2111650721 is an apocalyptic number.

It is an amenable number.

2111650721 is a deficient number, since it is larger than the sum of its proper divisors (1).

2111650721 is an equidigital number, since it uses as much as digits as its factorization.

2111650721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 840, while the sum is 26.

The square root of 2111650721 is about 45952.7009108279. The cubic root of 2111650721 is about 1282.9430005496.

The spelling of 2111650721 in words is "two billion, one hundred eleven million, six hundred fifty thousand, seven hundred twenty-one".