20001611 has 16 divisors (see below), whose sum is σ = 23347200. Its totient is φ = 16783200.

The previous prime is 20001557. The next prime is 20001613. The reversal of 20001611 is 11610002.

20001611 = 11² + 12² + ... + 391².

It is not a de Polignac number, because 20001611 - 2¹⁴ = 19985227 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20001592 and 20001601.

It is not an unprimeable number, because it can be changed into a prime (20001613) 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, 132386 + ... + 132536.

It is an arithmetic number, because the mean of its divisors is an integer number (1459200).

Almost surely, 2^20001611 is an apocalyptic number.

20001611 is a deficient number, since it is larger than the sum of its proper divisors (3345589).

20001611 is a wasteful number, since it uses less digits than its factorization.

20001611 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 434.

The product of its (nonzero) digits is 12, while the sum is 11.

The square root of 20001611 is about 4472.3160666482. The cubic root of 20001611 is about 271.4490496751.

Adding to 20001611 its reverse (11610002), we get a palindrome (31611613).

The spelling of 20001611 in words is "twenty million, one thousand, six hundred eleven".