20616531 has 8 divisors (see below), whose sum is σ = 29603280. Its totient is φ = 12687072.

The previous prime is 20616521. The next prime is 20616559. The reversal of 20616531 is 13561602.

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

It is not a de Polignac number, because 20616531 - 2¹¹ = 20614483 is a prime.

It is a super-2 number, since 2×20616531² = 850082700947922, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20616521) 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 7 ways as a sum of consecutive naturals, for example, 264276 + ... + 264353.

It is an arithmetic number, because the mean of its divisors is an integer number (3700410).

Almost surely, 2^20616531 is an apocalyptic number.

20616531 is a deficient number, since it is larger than the sum of its proper divisors (8986749).

20616531 is a wasteful number, since it uses less digits than its factorization.

20616531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 528645.

The product of its (nonzero) digits is 1080, while the sum is 24.

The square root of 20616531 is about 4540.5430291982. The cubic root of 20616531 is about 274.2027864612.

The spelling of 20616531 in words is "twenty million, six hundred sixteen thousand, five hundred thirty-one".