20011531666 has 16 divisors (see below), whose sum is σ = 34452722304. Its totient is φ = 8539560864.

The previous prime is 20011531621. The next prime is 20011531667. The reversal of 20011531666 is 66613511002.

It is a super-2 number, since 2×20011531666² (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 7 ways as a sum of consecutive naturals, for example, 3064110 + ... + 3070633.

It is an arithmetic number, because the mean of its divisors is an integer number (2153295144).

Almost surely, 2^20011531666 is an apocalyptic number.

20011531666 is a deficient number, since it is larger than the sum of its proper divisors (14441190638).

20011531666 is a wasteful number, since it uses less digits than its factorization.

20011531666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6134985.

The product of its (nonzero) digits is 6480, while the sum is 31.

The spelling of 20011531666 in words is "twenty billion, eleven million, five hundred thirty-one thousand, six hundred sixty-six".