20391608 has 32 divisors (see below), whose sum is σ = 39389760. Its totient is φ = 9891840.

The previous prime is 20391599. The next prime is 20391647. The reversal of 20391608 is 80619302.

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 7 ways as a sum of consecutive naturals, for example, 72428 + ... + 72708.

It is an arithmetic number, because the mean of its divisors is an integer number (1230930).

Almost surely, 2^20391608 is an apocalyptic number.

It is an amenable number.

20391608 is a deficient number, since it is larger than the sum of its proper divisors (18998152).

20391608 is a wasteful number, since it uses less digits than its factorization.

20391608 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 527 (or 523 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 29.

The square root of 20391608 is about 4515.7068106776. The cubic root of 20391608 is about 273.2019687353.

The spelling of 20391608 in words is "twenty million, three hundred ninety-one thousand, six hundred eight".