20423918 has 4 divisors (see below), whose sum is σ = 30635880. Its totient is φ = 10211958.

The previous prime is 20423911. The next prime is 20423927. The reversal of 20423918 is 81932402.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20423911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5105978 + ... + 5105981.

It is an arithmetic number, because the mean of its divisors is an integer number (7658970).

Almost surely, 2^20423918 is an apocalyptic number.

20423918 is a deficient number, since it is larger than the sum of its proper divisors (10211962).

20423918 is a wasteful number, since it uses less digits than its factorization.

20423918 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10211961.

The product of its (nonzero) digits is 3456, while the sum is 29.

The square root of 20423918 is about 4519.2829077189. The cubic root of 20423918 is about 273.3461865197.

The spelling of 20423918 in words is "twenty million, four hundred twenty-three thousand, nine hundred eighteen".