20011531665 has 16 divisors (see below), whose sum is σ = 32030748288. Its totient is φ = 10668717696.

The previous prime is 20011531621. The next prime is 20011531667. The reversal of 20011531665 is 56613511002.

It is not a de Polignac number, because 20011531665 - 2⁶ = 20011531601 is a prime.

It is a super-2 number, since 2×20011531665² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20011531667) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 215637 + ... + 294146.

It is an arithmetic number, because the mean of its divisors is an integer number (2001921768).

Almost surely, 2^20011531665 is an apocalyptic number.

It is an amenable number.

20011531665 is a deficient number, since it is larger than the sum of its proper divisors (12019216623).

20011531665 is a wasteful number, since it uses less digits than its factorization.

20011531665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 512408.

The product of its (nonzero) digits is 5400, while the sum is 30.

The spelling of 20011531665 in words is "twenty billion, eleven million, five hundred thirty-one thousand, six hundred sixty-five".