2116161621 has 24 divisors (see below), whose sum is σ = 3645233280. Its totient is φ = 1156658976.

The previous prime is 2116161617. The next prime is 2116161631. The reversal of 2116161621 is 1261616112.

2116161621 is a `hidden beast` number, since 2 + 11 + 616 + 16 + 21 = 666.

It is not a de Polignac number, because 2116161621 - 2² = 2116161617 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2116161631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 728766 + ... + 731663.

It is an arithmetic number, because the mean of its divisors is an integer number (151884720).

Almost surely, 2^2116161621 is an apocalyptic number.

2116161621 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

2116161621 is a deficient number, since it is larger than the sum of its proper divisors (1529071659).

2116161621 is a wasteful number, since it uses less digits than its factorization.

2116161621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1460465 (or 1460462 counting only the distinct ones).

The product of its digits is 864, while the sum is 27.

The square root of 2116161621 is about 46001.7567164559. The cubic root of 2116161621 is about 1283.8558900919.

Adding to 2116161621 its reverse (1261616112), we get a palindrome (3377777733).

The spelling of 2116161621 in words is "two billion, one hundred sixteen million, one hundred sixty-one thousand, six hundred twenty-one".