2161321636 has 12 divisors (see below), whose sum is σ = 3782816128. Its totient is φ = 1080517032.

The previous prime is 2161321627. The next prime is 2161321637. The reversal of 2161321636 is 6361231612.

It is a super-2 number, since 2×2161321636² = 9342622428483432992, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 2161321598 and 2161321607.

It is not an unprimeable number, because it can be changed into a prime (2161321637) 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, 2425 + ... + 65791.

Almost surely, 2^2161321636 is an apocalyptic number.

It is an amenable number.

2161321636 is a deficient number, since it is larger than the sum of its proper divisors (1621494492).

2161321636 is a wasteful number, since it uses less digits than its factorization.

2161321636 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71898 (or 71896 counting only the distinct ones).

The product of its digits is 7776, while the sum is 31.

The square root of 2161321636 is about 46490.0165196787. The cubic root of 2161321636 is about 1292.9244064175.

The spelling of 2161321636 in words is "two billion, one hundred sixty-one million, three hundred twenty-one thousand, six hundred thirty-six".