2011665621 has 8 divisors (see below), whose sum is σ = 3065395264. Its totient is φ = 1149523200.

The previous prime is 2011665589. The next prime is 2011665673. The reversal of 2011665621 is 1265661102.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 2011665621 - 2⁵ = 2011665589 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2011665421) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 47896780 + ... + 47896821.

It is an arithmetic number, because the mean of its divisors is an integer number (383174408).

Almost surely, 2^2011665621 is an apocalyptic number.

2011665621 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

2011665621 is a deficient number, since it is larger than the sum of its proper divisors (1053729643).

2011665621 is an equidigital number, since it uses as much as digits as its factorization.

2011665621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95793611.

The product of its (nonzero) digits is 4320, while the sum is 30.

The square root of 2011665621 is about 44851.5955234594. The cubic root of 2011665621 is about 1262.3659294417.

The spelling of 2011665621 in words is "two billion, eleven million, six hundred sixty-five thousand, six hundred twenty-one".