20564534 has 8 divisors (see below), whose sum is σ = 31599288. Its totient is φ = 10031440.

The previous prime is 20564513. The next prime is 20564561. The reversal of 20564534 is 43546502.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-3 number, since 3×20564534³ (a number of 23 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 20564497 and 20564506.

It is a congruent number.

It is an unprimeable number.

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, 125312 + ... + 125475.

It is an arithmetic number, because the mean of its divisors is an integer number (3949911).

Almost surely, 2^20564534 is an apocalyptic number.

20564534 is a deficient number, since it is larger than the sum of its proper divisors (11034754).

20564534 is a wasteful number, since it uses less digits than its factorization.

20564534 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 250830.

The product of its (nonzero) digits is 14400, while the sum is 29.

The square root of 20564534 is about 4534.8135573582. The cubic root of 20564534 is about 273.9720698971.

It can be divided in two parts, 205645 and 34, that multiplied together give a triangular number (6991930 = T₃₇₃₉).

The spelling of 20564534 in words is "twenty million, five hundred sixty-four thousand, five hundred thirty-four".