20723918 has 8 divisors (see below), whose sum is σ = 32914512. Its totient is φ = 9752416.

The previous prime is 20723891. The next prime is 20723921. The reversal of 20723918 is 81932702.

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

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, 304730 + ... + 304797.

It is an arithmetic number, because the mean of its divisors is an integer number (4114314).

Almost surely, 2^20723918 is an apocalyptic number.

20723918 is a deficient number, since it is larger than the sum of its proper divisors (12190594).

20723918 is a wasteful number, since it uses less digits than its factorization.

20723918 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 609546.

The product of its (nonzero) digits is 6048, while the sum is 32.

The square root of 20723918 is about 4552.3530179458. The cubic root of 20723918 is about 274.6780496770.

The spelling of 20723918 in words is "twenty million, seven hundred twenty-three thousand, nine hundred eighteen".