20745611 has 4 divisors (see below), whose sum is σ = 20895000. Its totient is φ = 20596224.

The previous prime is 20745583. The next prime is 20745623. The reversal of 20745611 is 11654702.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 11654702 = 2 ⋅5827351.

It is a cyclic number.

It is not a de Polignac number, because 20745611 - 2⁶ = 20745547 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20745691) 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 3 ways as a sum of consecutive naturals, for example, 74486 + ... + 74763.

It is an arithmetic number, because the mean of its divisors is an integer number (5223750).

Almost surely, 2^20745611 is an apocalyptic number.

20745611 is a deficient number, since it is larger than the sum of its proper divisors (149389).

20745611 is a wasteful number, since it uses less digits than its factorization.

20745611 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 149388.

The product of its (nonzero) digits is 1680, while the sum is 26.

The square root of 20745611 is about 4554.7350087574. The cubic root of 20745611 is about 274.7738570603.

Subtracting from 20745611 its reverse (11654702), we obtain a palindrome (9090909).

The spelling of 20745611 in words is "twenty million, seven hundred forty-five thousand, six hundred eleven".