20688461 has 12 divisors (see below), whose sum is σ = 21625632. Its totient is φ = 19786536.

The previous prime is 20688433. The next prime is 20688463. The reversal of 20688461 is 16488602.

It is not a de Polignac number, because 20688461 - 2¹⁸ = 20426317 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20688463) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 123800 + ... + 123966.

It is an arithmetic number, because the mean of its divisors is an integer number (1802136).

Almost surely, 2^20688461 is an apocalyptic number.

It is an amenable number.

20688461 is a deficient number, since it is larger than the sum of its proper divisors (937171).

20688461 is an equidigital number, since it uses as much as digits as its factorization.

20688461 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 320 (or 277 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 35.

The square root of 20688461 is about 4548.4569911125. The cubic root of 20688461 is about 274.5213093787.

The spelling of 20688461 in words is "twenty million, six hundred eighty-eight thousand, four hundred sixty-one".